diff --git a/java/com/google/gerrit/acceptance/AbstractDaemonTest.java b/java/com/google/gerrit/acceptance/AbstractDaemonTest.java
index 1d87880..69d603f 100644
--- a/java/com/google/gerrit/acceptance/AbstractDaemonTest.java
+++ b/java/com/google/gerrit/acceptance/AbstractDaemonTest.java
@@ -1487,12 +1487,7 @@
     assertNotifyTo(expected.email, expected.fullName);
   }
 
-  protected void assertNotifyTo(
-      com.google.gerrit.acceptance.testsuite.account.TestAccount expected) {
-    assertNotifyTo(expected.preferredEmail().orElse(null), expected.fullname().orElse(null));
-  }
-
-  private void assertNotifyTo(String expectedEmail, String expectedFullname) {
+  protected void assertNotifyTo(String expectedEmail, String expectedFullname) {
     Address expectedAddress = new Address(expectedFullname, expectedEmail);
     assertThat(sender.getMessages()).hasSize(1);
     Message m = sender.getMessages().get(0);
@@ -1506,11 +1501,6 @@
     assertNotifyCc(expected.emailAddress);
   }
 
-  protected void assertNotifyCc(
-      com.google.gerrit.acceptance.testsuite.account.TestAccount expected) {
-    assertNotifyCc(expected.preferredEmail().orElse(null), expected.fullname().orElse(null));
-  }
-
   protected void assertNotifyCc(String expectedEmail, String expectedFullname) {
     Address expectedAddress = new Address(expectedFullname, expectedEmail);
     assertNotifyCc(expectedAddress);
@@ -1533,13 +1523,10 @@
     assertThat(m.headers().get("Cc").isEmpty()).isTrue();
   }
 
-  protected void assertNotifyBcc(
-      com.google.gerrit.acceptance.testsuite.account.TestAccount expected) {
+  protected void assertNotifyBcc(String expectedEmail, String expectedFullName) {
     assertThat(sender.getMessages()).hasSize(1);
     Message m = sender.getMessages().get(0);
-    assertThat(m.rcpt())
-        .containsExactly(
-            new Address(expected.fullname().orElse(null), expected.preferredEmail().orElse(null)));
+    assertThat(m.rcpt()).containsExactly(new Address(expectedFullName, expectedEmail));
     assertThat(m.headers().get("To").isEmpty()).isTrue();
     assertThat(m.headers().get("Cc").isEmpty()).isTrue();
   }
diff --git a/java/com/google/gerrit/acceptance/GerritServer.java b/java/com/google/gerrit/acceptance/GerritServer.java
index 6e5424c..582c7cb 100644
--- a/java/com/google/gerrit/acceptance/GerritServer.java
+++ b/java/com/google/gerrit/acceptance/GerritServer.java
@@ -24,6 +24,8 @@
 import com.google.common.collect.ImmutableList;
 import com.google.gerrit.acceptance.testsuite.account.AccountOperations;
 import com.google.gerrit.acceptance.testsuite.account.AccountOperationsImpl;
+import com.google.gerrit.acceptance.testsuite.group.GroupOperations;
+import com.google.gerrit.acceptance.testsuite.group.GroupOperationsImpl;
 import com.google.gerrit.common.Nullable;
 import com.google.gerrit.extensions.config.FactoryModule;
 import com.google.gerrit.lucene.LuceneIndexModule;
@@ -441,6 +443,7 @@
             bindConstant().annotatedWith(SshEnabled.class).to(daemon.getEnableSshd());
             bind(AccountCreator.class);
             bind(AccountOperations.class).to(AccountOperationsImpl.class);
+            bind(GroupOperations.class).to(GroupOperationsImpl.class);
             factory(PushOneCommit.Factory.class);
             install(InProcessProtocol.module());
             install(new NoSshModule());
diff --git a/java/com/google/gerrit/acceptance/testsuite/account/AccountOperations.java b/java/com/google/gerrit/acceptance/testsuite/account/AccountOperations.java
index 58a00d0..61b7599 100644
--- a/java/com/google/gerrit/acceptance/testsuite/account/AccountOperations.java
+++ b/java/com/google/gerrit/acceptance/testsuite/account/AccountOperations.java
@@ -42,7 +42,7 @@
    * <p>Example:
    *
    * <pre>
-   * TestAccount createdAccount = accountOperations
+   * Account.Id createdAccountId = accountOperations
    *     .newAccount()
    *     .username("janedoe")
    *     .preferredEmail("janedoe@example.com")
diff --git a/java/com/google/gerrit/acceptance/testsuite/account/AccountOperationsImpl.java b/java/com/google/gerrit/acceptance/testsuite/account/AccountOperationsImpl.java
index 94b511b..ebbcfe4 100644
--- a/java/com/google/gerrit/acceptance/testsuite/account/AccountOperationsImpl.java
+++ b/java/com/google/gerrit/acceptance/testsuite/account/AccountOperationsImpl.java
@@ -59,12 +59,12 @@
     return TestAccountCreation.builder(this::createAccount);
   }
 
-  private TestAccount createAccount(TestAccountCreation accountCreation) throws Exception {
+  private Account.Id createAccount(TestAccountCreation accountCreation) throws Exception {
     AccountsUpdate.AccountUpdater accountUpdater =
         (account, updateBuilder) ->
             fillBuilder(updateBuilder, accountCreation, account.getAccount().getId());
     AccountState createdAccount = createAccount(accountUpdater);
-    return toTestAccount(createdAccount);
+    return createdAccount.getAccount().getId();
   }
 
   private AccountState createAccount(AccountsUpdate.AccountUpdater accountUpdater)
@@ -85,17 +85,6 @@
     accountCreation.active().ifPresent(builder::setActive);
   }
 
-  private static TestAccount toTestAccount(AccountState accountState) {
-    Account createdAccount = accountState.getAccount();
-    return TestAccount.builder()
-        .accountId(createdAccount.getId())
-        .preferredEmail(Optional.ofNullable(createdAccount.getPreferredEmail()))
-        .fullname(Optional.ofNullable(createdAccount.getFullName()))
-        .username(accountState.getUserName())
-        .active(accountState.getAccount().isActive())
-        .build();
-  }
-
   private static InternalAccountUpdate.Builder setPreferredEmail(
       InternalAccountUpdate.Builder builder, Account.Id accountId, String preferredEmail) {
     return builder
@@ -133,6 +122,17 @@
       return toTestAccount(account);
     }
 
+    private TestAccount toTestAccount(AccountState accountState) {
+      Account account = accountState.getAccount();
+      return TestAccount.builder()
+          .accountId(account.getId())
+          .preferredEmail(Optional.ofNullable(account.getPreferredEmail()))
+          .fullname(Optional.ofNullable(account.getFullName()))
+          .username(accountState.getUserName())
+          .active(accountState.getAccount().isActive())
+          .build();
+    }
+
     @Override
     public TestAccountUpdate.Builder forUpdate() {
       return TestAccountUpdate.builder(this::updateAccount);
diff --git a/java/com/google/gerrit/acceptance/testsuite/account/TestAccountCreation.java b/java/com/google/gerrit/acceptance/testsuite/account/TestAccountCreation.java
index a82d180..ab32409 100644
--- a/java/com/google/gerrit/acceptance/testsuite/account/TestAccountCreation.java
+++ b/java/com/google/gerrit/acceptance/testsuite/account/TestAccountCreation.java
@@ -16,6 +16,7 @@
 
 import com.google.auto.value.AutoValue;
 import com.google.gerrit.acceptance.testsuite.ThrowingFunction;
+import com.google.gerrit.reviewdb.client.Account;
 import java.util.Optional;
 
 @AutoValue
@@ -32,9 +33,9 @@
 
   public abstract Optional<Boolean> active();
 
-  abstract ThrowingFunction<TestAccountCreation, TestAccount> accountCreator();
+  abstract ThrowingFunction<TestAccountCreation, Account.Id> accountCreator();
 
-  public static Builder builder(ThrowingFunction<TestAccountCreation, TestAccount> accountCreator) {
+  public static Builder builder(ThrowingFunction<TestAccountCreation, Account.Id> accountCreator) {
     return new AutoValue_TestAccountCreation.Builder()
         .accountCreator(accountCreator)
         .httpPassword("http-pass");
@@ -83,11 +84,11 @@
     }
 
     abstract Builder accountCreator(
-        ThrowingFunction<TestAccountCreation, TestAccount> accountCreator);
+        ThrowingFunction<TestAccountCreation, Account.Id> accountCreator);
 
     abstract TestAccountCreation autoBuild();
 
-    public TestAccount create() throws Exception {
+    public Account.Id create() throws Exception {
       TestAccountCreation accountUpdate = autoBuild();
       return accountUpdate.accountCreator().apply(accountUpdate);
     }
diff --git a/java/com/google/gerrit/acceptance/testsuite/group/GroupOperations.java b/java/com/google/gerrit/acceptance/testsuite/group/GroupOperations.java
new file mode 100644
index 0000000..f75ca2e
--- /dev/null
+++ b/java/com/google/gerrit/acceptance/testsuite/group/GroupOperations.java
@@ -0,0 +1,97 @@
+// Copyright (C) 2018 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.acceptance.testsuite.group;
+
+import com.google.gerrit.reviewdb.client.AccountGroup;
+
+/**
+ * An aggregation of operations on groups for test purposes.
+ *
+ * <p>To execute the operations, no Gerrit permissions are necessary.
+ *
+ * <p><strong>Note:</strong> This interface is not implemented using the REST or extension API.
+ * Hence, it cannot be used for testing those APIs.
+ */
+public interface GroupOperations {
+  /**
+   * Starts the fluent chain for querying or modifying a group. Please see the methods of {@link
+   * MoreGroupOperations} for details on possible operations.
+   *
+   * @return an aggregation of operations on a specific group
+   */
+  MoreGroupOperations group(AccountGroup.UUID groupUuid);
+
+  /**
+   * Starts the fluent chain to create a group. The returned builder can be used to specify the
+   * attributes of the new group. To create the group for real, {@link
+   * TestGroupCreation.Builder#create()} must be called.
+   *
+   * <p>Example:
+   *
+   * <pre>
+   * AccountGroup.UUID createdGroupUuid = groupOperations
+   *     .newGroup()
+   *     .name("verifiers")
+   *     .description("All verifiers of this server")
+   *     .create();
+   * </pre>
+   *
+   * <p><strong>Note:</strong> If another group with the provided name already exists, the creation
+   * of the group will fail.
+   *
+   * @return a builder to create the new group
+   */
+  TestGroupCreation.Builder newGroup();
+
+  /** An aggregation of methods on a specific group. */
+  interface MoreGroupOperations {
+
+    /**
+     * Checks whether the group exists.
+     *
+     * @return {@code true} if the group exists
+     */
+    boolean exists() throws Exception;
+
+    /**
+     * Retrieves the group.
+     *
+     * <p><strong>Note:</strong> This call will fail with an exception if the requested group
+     * doesn't exist. If you want to check for the existence of a group, use {@link #exists()}
+     * instead.
+     *
+     * @return the corresponding {@code TestGroup}
+     */
+    TestGroup get() throws Exception;
+
+    /**
+     * Starts the fluent chain to update a group. The returned builder can be used to specify how
+     * the attributes of the group should be modified. To update the group for real, {@link
+     * TestGroupUpdate.Builder#update()} must be called.
+     *
+     * <p>Example:
+     *
+     * <pre>
+     * groupOperations.forUpdate().description("Another description for this group").update();
+     * </pre>
+     *
+     * <p><strong>Note:</strong> The update will fail with an exception if the group to update
+     * doesn't exist. If you want to check for the existence of a group, use {@link #exists()}.
+     *
+     * @return a builder to update the group
+     */
+    TestGroupUpdate.Builder forUpdate();
+  }
+}
diff --git a/java/com/google/gerrit/acceptance/testsuite/group/GroupOperationsImpl.java b/java/com/google/gerrit/acceptance/testsuite/group/GroupOperationsImpl.java
new file mode 100644
index 0000000..f9769c5
--- /dev/null
+++ b/java/com/google/gerrit/acceptance/testsuite/group/GroupOperationsImpl.java
@@ -0,0 +1,159 @@
+// Copyright (C) 2018 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.acceptance.testsuite.group;
+
+import static com.google.common.base.Preconditions.checkState;
+
+import com.google.gerrit.common.errors.NoSuchGroupException;
+import com.google.gerrit.reviewdb.client.AccountGroup;
+import com.google.gerrit.server.GerritPersonIdent;
+import com.google.gerrit.server.Sequences;
+import com.google.gerrit.server.ServerInitiated;
+import com.google.gerrit.server.account.GroupUUID;
+import com.google.gerrit.server.group.InternalGroup;
+import com.google.gerrit.server.group.db.Groups;
+import com.google.gerrit.server.group.db.GroupsUpdate;
+import com.google.gerrit.server.group.db.InternalGroupCreation;
+import com.google.gerrit.server.group.db.InternalGroupUpdate;
+import com.google.gwtorm.server.OrmDuplicateKeyException;
+import com.google.gwtorm.server.OrmException;
+import com.google.inject.Inject;
+import java.io.IOException;
+import java.util.Optional;
+import org.eclipse.jgit.errors.ConfigInvalidException;
+import org.eclipse.jgit.lib.PersonIdent;
+
+/**
+ * The implementation of {@code GroupOperations}.
+ *
+ * <p>There is only one implementation of {@code GroupOperations}. Nevertheless, we keep the
+ * separation between interface and implementation to enhance clarity.
+ */
+public class GroupOperationsImpl implements GroupOperations {
+  private final Groups groups;
+  private final GroupsUpdate groupsUpdate;
+  private final Sequences seq;
+  private final PersonIdent serverIdent;
+
+  @Inject
+  public GroupOperationsImpl(
+      Groups groups,
+      @ServerInitiated GroupsUpdate groupsUpdate,
+      Sequences seq,
+      @GerritPersonIdent PersonIdent serverIdent) {
+    this.groups = groups;
+    this.groupsUpdate = groupsUpdate;
+    this.seq = seq;
+    this.serverIdent = serverIdent;
+  }
+
+  @Override
+  public MoreGroupOperations group(AccountGroup.UUID groupUuid) {
+    return new MoreGroupOperationsImpl(groupUuid);
+  }
+
+  @Override
+  public TestGroupCreation.Builder newGroup() {
+    return TestGroupCreation.builder(this::createNewGroup);
+  }
+
+  private AccountGroup.UUID createNewGroup(TestGroupCreation groupCreation)
+      throws ConfigInvalidException, IOException, OrmException {
+    InternalGroupCreation internalGroupCreation = toInternalGroupCreation(groupCreation);
+    InternalGroupUpdate internalGroupUpdate = toInternalGroupUpdate(groupCreation);
+    InternalGroup internalGroup =
+        groupsUpdate.createGroup(internalGroupCreation, internalGroupUpdate);
+    return internalGroup.getGroupUUID();
+  }
+
+  private InternalGroupCreation toInternalGroupCreation(TestGroupCreation groupCreation)
+      throws OrmException {
+    AccountGroup.Id groupId = new AccountGroup.Id(seq.nextGroupId());
+    String groupName = groupCreation.name().orElse("group-with-id-" + groupId.get());
+    AccountGroup.UUID groupUuid = GroupUUID.make(groupName, serverIdent);
+    AccountGroup.NameKey nameKey = new AccountGroup.NameKey(groupName);
+    return InternalGroupCreation.builder()
+        .setId(groupId)
+        .setGroupUUID(groupUuid)
+        .setNameKey(nameKey)
+        .build();
+  }
+
+  private static InternalGroupUpdate toInternalGroupUpdate(TestGroupCreation groupCreation) {
+    InternalGroupUpdate.Builder builder = InternalGroupUpdate.builder();
+    groupCreation.description().ifPresent(builder::setDescription);
+    groupCreation.ownerGroupUuid().ifPresent(builder::setOwnerGroupUUID);
+    groupCreation.visibleToAll().ifPresent(builder::setVisibleToAll);
+    builder.setMemberModification(originalMembers -> groupCreation.members());
+    builder.setSubgroupModification(originalSubgroups -> groupCreation.subgroups());
+    return builder.build();
+  }
+
+  private class MoreGroupOperationsImpl implements MoreGroupOperations {
+    private final AccountGroup.UUID groupUuid;
+
+    MoreGroupOperationsImpl(AccountGroup.UUID groupUuid) {
+      this.groupUuid = groupUuid;
+    }
+
+    @Override
+    public boolean exists() throws Exception {
+      return groups.getGroup(groupUuid).isPresent();
+    }
+
+    @Override
+    public TestGroup get() throws Exception {
+      Optional<InternalGroup> group = groups.getGroup(groupUuid);
+      checkState(group.isPresent(), "Tried to get non-existing test group");
+      return toTestGroup(group.get());
+    }
+
+    private TestGroup toTestGroup(InternalGroup internalGroup) {
+      return TestGroup.builder()
+          .groupUuid(internalGroup.getGroupUUID())
+          .groupId(internalGroup.getId())
+          .nameKey(internalGroup.getNameKey())
+          .description(Optional.ofNullable(internalGroup.getDescription()))
+          .ownerGroupUuid(internalGroup.getOwnerGroupUUID())
+          .visibleToAll(internalGroup.isVisibleToAll())
+          .createdOn(internalGroup.getCreatedOn())
+          .members(internalGroup.getMembers())
+          .subgroups(internalGroup.getSubgroups())
+          .build();
+    }
+
+    @Override
+    public TestGroupUpdate.Builder forUpdate() {
+      return TestGroupUpdate.builder(this::updateGroup);
+    }
+
+    private void updateGroup(TestGroupUpdate groupUpdate)
+        throws OrmDuplicateKeyException, NoSuchGroupException, ConfigInvalidException, IOException {
+      InternalGroupUpdate internalGroupUpdate = toInternalGroupUpdate(groupUpdate);
+      groupsUpdate.updateGroup(groupUuid, internalGroupUpdate);
+    }
+
+    private InternalGroupUpdate toInternalGroupUpdate(TestGroupUpdate groupUpdate) {
+      InternalGroupUpdate.Builder builder = InternalGroupUpdate.builder();
+      groupUpdate.name().map(AccountGroup.NameKey::new).ifPresent(builder::setName);
+      groupUpdate.description().ifPresent(builder::setDescription);
+      groupUpdate.ownerGroupUuid().ifPresent(builder::setOwnerGroupUUID);
+      groupUpdate.visibleToAll().ifPresent(builder::setVisibleToAll);
+      builder.setMemberModification(groupUpdate.memberModification()::apply);
+      builder.setSubgroupModification(groupUpdate.subgroupModification()::apply);
+      return builder.build();
+    }
+  }
+}
diff --git a/java/com/google/gerrit/acceptance/testsuite/group/TestGroup.java b/java/com/google/gerrit/acceptance/testsuite/group/TestGroup.java
new file mode 100644
index 0000000..b450304
--- /dev/null
+++ b/java/com/google/gerrit/acceptance/testsuite/group/TestGroup.java
@@ -0,0 +1,78 @@
+// Copyright (C) 2018 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.acceptance.testsuite.group;
+
+import com.google.auto.value.AutoValue;
+import com.google.common.collect.ImmutableSet;
+import com.google.gerrit.reviewdb.client.Account;
+import com.google.gerrit.reviewdb.client.AccountGroup;
+import java.sql.Timestamp;
+import java.util.Optional;
+
+@AutoValue
+public abstract class TestGroup {
+
+  public abstract AccountGroup.UUID groupUuid();
+
+  public abstract AccountGroup.Id groupId();
+
+  public String name() {
+    return nameKey().get();
+  }
+
+  public abstract AccountGroup.NameKey nameKey();
+
+  public abstract Optional<String> description();
+
+  public abstract AccountGroup.UUID ownerGroupUuid();
+
+  public abstract boolean visibleToAll();
+
+  public abstract Timestamp createdOn();
+
+  public abstract ImmutableSet<Account.Id> members();
+
+  public abstract ImmutableSet<AccountGroup.UUID> subgroups();
+
+  static Builder builder() {
+    return new AutoValue_TestGroup.Builder();
+  }
+
+  @AutoValue.Builder
+  abstract static class Builder {
+
+    public abstract Builder groupUuid(AccountGroup.UUID groupUuid);
+
+    public abstract Builder groupId(AccountGroup.Id id);
+
+    public abstract Builder nameKey(AccountGroup.NameKey name);
+
+    public abstract Builder description(String description);
+
+    public abstract Builder description(Optional<String> description);
+
+    public abstract Builder ownerGroupUuid(AccountGroup.UUID ownerGroupUuid);
+
+    public abstract Builder visibleToAll(boolean visibleToAll);
+
+    public abstract Builder createdOn(Timestamp createdOn);
+
+    public abstract Builder members(ImmutableSet<Account.Id> members);
+
+    public abstract Builder subgroups(ImmutableSet<AccountGroup.UUID> subgroups);
+
+    abstract TestGroup build();
+  }
+}
diff --git a/java/com/google/gerrit/acceptance/testsuite/group/TestGroupCreation.java b/java/com/google/gerrit/acceptance/testsuite/group/TestGroupCreation.java
new file mode 100644
index 0000000..efed720
--- /dev/null
+++ b/java/com/google/gerrit/acceptance/testsuite/group/TestGroupCreation.java
@@ -0,0 +1,112 @@
+// Copyright (C) 2018 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.acceptance.testsuite.group;
+
+import com.google.auto.value.AutoValue;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Sets;
+import com.google.gerrit.acceptance.testsuite.ThrowingFunction;
+import com.google.gerrit.reviewdb.client.Account;
+import com.google.gerrit.reviewdb.client.AccountGroup;
+import java.util.Optional;
+import java.util.Set;
+
+@AutoValue
+public abstract class TestGroupCreation {
+
+  public abstract Optional<String> name();
+
+  public abstract Optional<String> description();
+
+  public abstract Optional<AccountGroup.UUID> ownerGroupUuid();
+
+  public abstract Optional<Boolean> visibleToAll();
+
+  public abstract ImmutableSet<Account.Id> members();
+
+  public abstract ImmutableSet<AccountGroup.UUID> subgroups();
+
+  abstract ThrowingFunction<TestGroupCreation, AccountGroup.UUID> groupCreator();
+
+  public static Builder builder(
+      ThrowingFunction<TestGroupCreation, AccountGroup.UUID> groupCreator) {
+    return new AutoValue_TestGroupCreation.Builder().groupCreator(groupCreator);
+  }
+
+  @AutoValue.Builder
+  public abstract static class Builder {
+
+    public abstract Builder name(String name);
+
+    public abstract Builder description(String description);
+
+    public Builder clearDescription() {
+      return description("");
+    }
+
+    public abstract Builder ownerGroupUuid(AccountGroup.UUID ownerGroupUuid);
+
+    public abstract Builder visibleToAll(boolean visibleToAll);
+
+    public Builder clearMembers() {
+      return members(ImmutableSet.of());
+    }
+
+    public Builder members(Account.Id member1, Account.Id... otherMembers) {
+      return members(Sets.union(ImmutableSet.of(member1), ImmutableSet.copyOf(otherMembers)));
+    }
+
+    public abstract Builder members(Set<Account.Id> members);
+
+    abstract ImmutableSet.Builder<Account.Id> membersBuilder();
+
+    public Builder addMember(Account.Id member) {
+      membersBuilder().add(member);
+      return this;
+    }
+
+    public Builder clearSubgroups() {
+      return subgroups(ImmutableSet.of());
+    }
+
+    public Builder subgroups(AccountGroup.UUID subgroup1, AccountGroup.UUID... otherSubgroups) {
+      return subgroups(Sets.union(ImmutableSet.of(subgroup1), ImmutableSet.copyOf(otherSubgroups)));
+    }
+
+    public abstract Builder subgroups(Set<AccountGroup.UUID> subgroups);
+
+    abstract ImmutableSet.Builder<AccountGroup.UUID> subgroupsBuilder();
+
+    public Builder addSubgroup(AccountGroup.UUID subgroup) {
+      subgroupsBuilder().add(subgroup);
+      return this;
+    }
+
+    abstract Builder groupCreator(
+        ThrowingFunction<TestGroupCreation, AccountGroup.UUID> groupCreator);
+
+    abstract TestGroupCreation autoBuild();
+
+    /**
+     * Executes the group creation as specified.
+     *
+     * @return the UUID of the created group
+     */
+    public AccountGroup.UUID create() throws Exception {
+      TestGroupCreation groupCreation = autoBuild();
+      return groupCreation.groupCreator().apply(groupCreation);
+    }
+  }
+}
diff --git a/java/com/google/gerrit/acceptance/testsuite/group/TestGroupUpdate.java b/java/com/google/gerrit/acceptance/testsuite/group/TestGroupUpdate.java
new file mode 100644
index 0000000..095a270
--- /dev/null
+++ b/java/com/google/gerrit/acceptance/testsuite/group/TestGroupUpdate.java
@@ -0,0 +1,134 @@
+// Copyright (C) 2018 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.acceptance.testsuite.group;
+
+import com.google.auto.value.AutoValue;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Sets;
+import com.google.gerrit.acceptance.testsuite.ThrowingConsumer;
+import com.google.gerrit.reviewdb.client.Account;
+import com.google.gerrit.reviewdb.client.AccountGroup;
+import java.util.Optional;
+import java.util.Set;
+import java.util.function.Function;
+
+@AutoValue
+public abstract class TestGroupUpdate {
+
+  public abstract Optional<String> name();
+
+  public abstract Optional<String> description();
+
+  public abstract Optional<AccountGroup.UUID> ownerGroupUuid();
+
+  public abstract Optional<Boolean> visibleToAll();
+
+  public abstract Function<ImmutableSet<Account.Id>, Set<Account.Id>> memberModification();
+
+  public abstract Function<ImmutableSet<AccountGroup.UUID>, Set<AccountGroup.UUID>>
+      subgroupModification();
+
+  abstract ThrowingConsumer<TestGroupUpdate> groupUpdater();
+
+  public static Builder builder(ThrowingConsumer<TestGroupUpdate> groupUpdater) {
+    return new AutoValue_TestGroupUpdate.Builder()
+        .groupUpdater(groupUpdater)
+        .memberModification(in -> in)
+        .subgroupModification(in -> in);
+  }
+
+  @AutoValue.Builder
+  public abstract static class Builder {
+
+    public abstract Builder name(String name);
+
+    public abstract Builder description(String description);
+
+    public Builder clearDescription() {
+      return description("");
+    }
+
+    public abstract Builder ownerGroupUuid(AccountGroup.UUID ownerGroupUUID);
+
+    public abstract Builder visibleToAll(boolean visibleToAll);
+
+    abstract Builder memberModification(
+        Function<ImmutableSet<Account.Id>, Set<Account.Id>> memberModification);
+
+    abstract Function<ImmutableSet<Account.Id>, Set<Account.Id>> memberModification();
+
+    public Builder clearMembers() {
+      return memberModification(originalMembers -> ImmutableSet.of());
+    }
+
+    public Builder addMember(Account.Id member) {
+      Function<ImmutableSet<Account.Id>, Set<Account.Id>> previousModification =
+          memberModification();
+      memberModification(
+          originalMembers ->
+              Sets.union(previousModification.apply(originalMembers), ImmutableSet.of(member)));
+      return this;
+    }
+
+    public Builder removeMember(Account.Id member) {
+      Function<ImmutableSet<Account.Id>, Set<Account.Id>> previousModification =
+          memberModification();
+      memberModification(
+          originalMembers ->
+              Sets.difference(
+                  previousModification.apply(originalMembers), ImmutableSet.of(member)));
+      return this;
+    }
+
+    abstract Builder subgroupModification(
+        Function<ImmutableSet<AccountGroup.UUID>, Set<AccountGroup.UUID>> subgroupModification);
+
+    abstract Function<ImmutableSet<AccountGroup.UUID>, Set<AccountGroup.UUID>>
+        subgroupModification();
+
+    public Builder clearSubgroups() {
+      return subgroupModification(originalMembers -> ImmutableSet.of());
+    }
+
+    public Builder addSubgroup(AccountGroup.UUID subgroup) {
+      Function<ImmutableSet<AccountGroup.UUID>, Set<AccountGroup.UUID>> previousModification =
+          subgroupModification();
+      subgroupModification(
+          originalSubgroups ->
+              Sets.union(previousModification.apply(originalSubgroups), ImmutableSet.of(subgroup)));
+      return this;
+    }
+
+    public Builder removeSubgroup(AccountGroup.UUID subgroup) {
+      Function<ImmutableSet<AccountGroup.UUID>, Set<AccountGroup.UUID>> previousModification =
+          subgroupModification();
+      subgroupModification(
+          originalSubgroups ->
+              Sets.difference(
+                  previousModification.apply(originalSubgroups), ImmutableSet.of(subgroup)));
+      return this;
+    }
+
+    abstract Builder groupUpdater(ThrowingConsumer<TestGroupUpdate> groupUpdater);
+
+    abstract TestGroupUpdate autoBuild();
+
+    /** Executes the group update as specified. */
+    public void update() throws Exception {
+      TestGroupUpdate groupUpdater = autoBuild();
+      groupUpdater.groupUpdater().accept(groupUpdater);
+    }
+  }
+}
diff --git a/javatests/com/google/gerrit/acceptance/api/accounts/AccountIT.java b/javatests/com/google/gerrit/acceptance/api/accounts/AccountIT.java
index b362b2b..7126354 100644
--- a/javatests/com/google/gerrit/acceptance/api/accounts/AccountIT.java
+++ b/javatests/com/google/gerrit/acceptance/api/accounts/AccountIT.java
@@ -526,9 +526,9 @@
 
   @Test
   public void validateAccountActivation() throws Exception {
-    com.google.gerrit.acceptance.testsuite.account.TestAccount activatableAccount =
+    Account.Id activatableAccountId =
         accountOperations.newAccount().inactive().preferredEmail("foo@activatable.com").create();
-    com.google.gerrit.acceptance.testsuite.account.TestAccount deactivatableAccount =
+    Account.Id deactivatableAccountId =
         accountOperations.newAccount().preferredEmail("foo@deactivatable.com").create();
     RegistrationHandle registrationHandle =
         accountActivationValidationListeners.add(
@@ -554,61 +554,56 @@
       /* Test account that can be activated, but not deactivated */
       // Deactivate account that is already inactive
       try {
-        gApi.accounts().id(activatableAccount.accountId().get()).setActive(false);
+        gApi.accounts().id(activatableAccountId.get()).setActive(false);
         fail("Expected exception");
       } catch (ResourceConflictException e) {
         assertThat(e.getMessage()).isEqualTo("account not active");
       }
-      assertThat(accountOperations.account(activatableAccount.accountId()).get().active())
-          .isFalse();
+      assertThat(accountOperations.account(activatableAccountId).get().active()).isFalse();
 
       // Activate account that can be activated
-      gApi.accounts().id(activatableAccount.accountId().get()).setActive(true);
-      assertThat(accountOperations.account(activatableAccount.accountId()).get().active()).isTrue();
+      gApi.accounts().id(activatableAccountId.get()).setActive(true);
+      assertThat(accountOperations.account(activatableAccountId).get().active()).isTrue();
 
       // Activate account that is already active
-      gApi.accounts().id(activatableAccount.accountId().get()).setActive(true);
-      assertThat(accountOperations.account(activatableAccount.accountId()).get().active()).isTrue();
+      gApi.accounts().id(activatableAccountId.get()).setActive(true);
+      assertThat(accountOperations.account(activatableAccountId).get().active()).isTrue();
 
       // Try deactivating account that cannot be deactivated
       try {
-        gApi.accounts().id(activatableAccount.accountId().get()).setActive(false);
+        gApi.accounts().id(activatableAccountId.get()).setActive(false);
         fail("Expected exception");
       } catch (ResourceConflictException e) {
         assertThat(e.getMessage()).isEqualTo("not allowed to deactive account");
       }
-      assertThat(accountOperations.account(activatableAccount.accountId()).get().active()).isTrue();
+      assertThat(accountOperations.account(activatableAccountId).get().active()).isTrue();
 
       /* Test account that can be deactivated, but not activated */
       // Activate account that is already inactive
-      gApi.accounts().id(deactivatableAccount.accountId().get()).setActive(true);
-      assertThat(accountOperations.account(deactivatableAccount.accountId()).get().active())
-          .isTrue();
+      gApi.accounts().id(deactivatableAccountId.get()).setActive(true);
+      assertThat(accountOperations.account(deactivatableAccountId).get().active()).isTrue();
 
       // Deactivate account that can be deactivated
-      gApi.accounts().id(deactivatableAccount.accountId().get()).setActive(false);
-      assertThat(accountOperations.account(deactivatableAccount.accountId()).get().active())
-          .isFalse();
+      gApi.accounts().id(deactivatableAccountId.get()).setActive(false);
+      assertThat(accountOperations.account(deactivatableAccountId).get().active()).isFalse();
 
       // Deactivate account that is already inactive
       try {
-        gApi.accounts().id(deactivatableAccount.accountId().get()).setActive(false);
+        gApi.accounts().id(deactivatableAccountId.get()).setActive(false);
         fail("Expected exception");
       } catch (ResourceConflictException e) {
         assertThat(e.getMessage()).isEqualTo("account not active");
       }
-      assertThat(accountOperations.account(deactivatableAccount.accountId()).get().active())
-          .isFalse();
+      assertThat(accountOperations.account(deactivatableAccountId).get().active()).isFalse();
 
       // Try activating account that cannot be activated
       try {
-        gApi.accounts().id(deactivatableAccount.accountId().get()).setActive(true);
+        gApi.accounts().id(deactivatableAccountId.get()).setActive(true);
         fail("Expected exception");
       } catch (ResourceConflictException e) {
         assertThat(e.getMessage()).isEqualTo("not allowed to active account");
       }
-      assertThat(accountOperations.account(deactivatableAccount.accountId()).get().active())
-          .isFalse();
+      assertThat(accountOperations.account(deactivatableAccountId).get().active()).isFalse();
     } finally {
       registrationHandle.remove();
     }
diff --git a/javatests/com/google/gerrit/acceptance/api/change/ChangeIT.java b/javatests/com/google/gerrit/acceptance/api/change/ChangeIT.java
index fe55115..b3a5e2d 100644
--- a/javatests/com/google/gerrit/acceptance/api/change/ChangeIT.java
+++ b/javatests/com/google/gerrit/acceptance/api/change/ChangeIT.java
@@ -68,7 +68,6 @@
 import com.google.gerrit.acceptance.PushOneCommit;
 import com.google.gerrit.acceptance.TestProjectInput;
 import com.google.gerrit.acceptance.testsuite.account.AccountOperations;
-import com.google.gerrit.acceptance.testsuite.account.TestAccount;
 import com.google.gerrit.common.FooterConstants;
 import com.google.gerrit.common.TimeUtil;
 import com.google.gerrit.common.data.LabelFunction;
@@ -1688,7 +1687,7 @@
     // create a group named "ab" with one user: testUser
     String email = "abcd@test.com";
     String fullname = "abcd";
-    TestAccount testUser =
+    Account.Id accountIdOfTestUser =
         accountOperations
             .newAccount()
             .username("abcd")
@@ -1721,7 +1720,7 @@
     Collection<AccountInfo> reviewers = c.reviewers.get(REVIEWER);
     assertThat(reviewers).isNotNull();
     assertThat(reviewers).hasSize(1);
-    assertThat(reviewers.iterator().next()._accountId).isEqualTo(testUser.accountId().get());
+    assertThat(reviewers.iterator().next()._accountId).isEqualTo(accountIdOfTestUser.get());
 
     // Ensure ETag and lastUpdatedOn are updated.
     rsrc = parseResource(r);
@@ -1748,7 +1747,7 @@
 
     String myGroupUserEmail = "lee@test.com";
     String myGroupUserFullname = "lee";
-    TestAccount myGroupUser =
+    Account.Id accountIdOfGroupUser =
         accountOperations
             .newAccount()
             .username("lee")
@@ -1785,7 +1784,7 @@
     Collection<AccountInfo> reviewers = c.reviewers.get(REVIEWER);
     assertThat(reviewers).isNotNull();
     assertThat(reviewers).hasSize(1);
-    assertThat(reviewers.iterator().next()._accountId).isEqualTo(myGroupUser.accountId().get());
+    assertThat(reviewers.iterator().next()._accountId).isEqualTo(accountIdOfGroupUser.get());
 
     // Ensure ETag and lastUpdatedOn are updated.
     rsrc = parseResource(r);
@@ -2215,13 +2214,12 @@
 
     // notify unrelated account as TO
     String email = "user2@example.com";
-    TestAccount user2 =
-        accountOperations
-            .newAccount()
-            .username("user2")
-            .preferredEmail(email)
-            .fullname("User2")
-            .create();
+    accountOperations
+        .newAccount()
+        .username("user2")
+        .preferredEmail(email)
+        .fullname("User2")
+        .create();
     setApiUser(user);
     recommend(r.getChangeId());
     setApiUser(admin);
@@ -2229,7 +2227,7 @@
     in.notifyDetails = new HashMap<>();
     in.notifyDetails.put(RecipientType.TO, new NotifyInfo(ImmutableList.of(email)));
     gApi.changes().id(r.getChangeId()).reviewer(user.getId().toString()).deleteVote(in);
-    assertNotifyTo(user2);
+    assertNotifyTo(email, "User2");
 
     // notify unrelated account as CC
     setApiUser(user);
@@ -2239,7 +2237,7 @@
     in.notifyDetails = new HashMap<>();
     in.notifyDetails.put(RecipientType.CC, new NotifyInfo(ImmutableList.of(email)));
     gApi.changes().id(r.getChangeId()).reviewer(user.getId().toString()).deleteVote(in);
-    assertNotifyCc(user2);
+    assertNotifyCc(email, "User2");
 
     // notify unrelated account as BCC
     setApiUser(user);
@@ -2249,7 +2247,7 @@
     in.notifyDetails = new HashMap<>();
     in.notifyDetails.put(RecipientType.BCC, new NotifyInfo(ImmutableList.of(email)));
     gApi.changes().id(r.getChangeId()).reviewer(user.getId().toString()).deleteVote(in);
-    assertNotifyBcc(user2);
+    assertNotifyBcc(email, "User2");
   }
 
   @Test
diff --git a/javatests/com/google/gerrit/acceptance/api/group/GroupsIT.java b/javatests/com/google/gerrit/acceptance/api/group/GroupsIT.java
index 8f1bdbc..d6be960 100644
--- a/javatests/com/google/gerrit/acceptance/api/group/GroupsIT.java
+++ b/javatests/com/google/gerrit/acceptance/api/group/GroupsIT.java
@@ -183,24 +183,23 @@
   @Test
   public void cachedGroupsForMemberAreUpdatedOnMemberAdditionAndRemoval() throws Exception {
     String username = name("user");
-    com.google.gerrit.acceptance.testsuite.account.TestAccount account =
-        accountOperations.newAccount().username(username).create();
+    Account.Id accountId = accountOperations.newAccount().username(username).create();
 
     // Fill the cache for the observed account.
-    groupIncludeCache.getGroupsWithMember(account.accountId());
+    groupIncludeCache.getGroupsWithMember(accountId);
     String groupName = createGroup("users");
     AccountGroup.UUID groupUuid = new AccountGroup.UUID(gApi.groups().id(groupName).get().id);
 
     gApi.groups().id(groupName).addMembers(username);
 
     Collection<AccountGroup.UUID> groupsWithMemberAfterAddition =
-        groupIncludeCache.getGroupsWithMember(account.accountId());
+        groupIncludeCache.getGroupsWithMember(accountId);
     assertThat(groupsWithMemberAfterAddition).contains(groupUuid);
 
     gApi.groups().id(groupName).removeMembers(username);
 
     Collection<AccountGroup.UUID> groupsWithMemberAfterRemoval =
-        groupIncludeCache.getGroupsWithMember(account.accountId());
+        groupIncludeCache.getGroupsWithMember(accountId);
     assertThat(groupsWithMemberAfterRemoval).doesNotContain(groupUuid);
   }
 
@@ -411,19 +410,17 @@
 
   @Test
   public void cachedGroupsForMemberAreUpdatedOnGroupCreation() throws Exception {
-    com.google.gerrit.acceptance.testsuite.account.TestAccount account =
-        accountOperations.newAccount().create();
+    Account.Id accountId = accountOperations.newAccount().create();
 
     // Fill the cache for the observed account.
-    groupIncludeCache.getGroupsWithMember(account.accountId());
+    groupIncludeCache.getGroupsWithMember(accountId);
 
     GroupInput groupInput = new GroupInput();
     groupInput.name = name("Users");
-    groupInput.members = ImmutableList.of(String.valueOf(account.accountId().get()));
+    groupInput.members = ImmutableList.of(String.valueOf(accountId.get()));
     GroupInfo group = gApi.groups().create(groupInput).get();
 
-    Collection<AccountGroup.UUID> groups =
-        groupIncludeCache.getGroupsWithMember(account.accountId());
+    Collection<AccountGroup.UUID> groups = groupIncludeCache.getGroupsWithMember(accountId);
     assertThat(groups).containsExactly(new AccountGroup.UUID(group.id));
   }
 
diff --git a/javatests/com/google/gerrit/acceptance/api/project/CheckAccessIT.java b/javatests/com/google/gerrit/acceptance/api/project/CheckAccessIT.java
index 2b1416a..e4194a3 100644
--- a/javatests/com/google/gerrit/acceptance/api/project/CheckAccessIT.java
+++ b/javatests/com/google/gerrit/acceptance/api/project/CheckAccessIT.java
@@ -20,16 +20,18 @@
 import com.google.gerrit.acceptance.AbstractDaemonTest;
 import com.google.gerrit.acceptance.RestResponse;
 import com.google.gerrit.acceptance.TestAccount;
+import com.google.gerrit.acceptance.testsuite.group.GroupOperations;
 import com.google.gerrit.common.data.Permission;
 import com.google.gerrit.extensions.api.config.AccessCheckInfo;
 import com.google.gerrit.extensions.api.config.AccessCheckInput;
 import com.google.gerrit.extensions.restapi.BadRequestException;
 import com.google.gerrit.extensions.restapi.RestApiException;
 import com.google.gerrit.extensions.restapi.UnprocessableEntityException;
+import com.google.gerrit.reviewdb.client.AccountGroup;
 import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.reviewdb.client.RefNames;
-import com.google.gerrit.server.group.InternalGroup;
 import com.google.gerrit.server.group.SystemGroupBackend;
+import com.google.inject.Inject;
 import java.util.List;
 import org.eclipse.jgit.lib.RefUpdate;
 import org.eclipse.jgit.lib.RefUpdate.Result;
@@ -39,35 +41,29 @@
 
 public class CheckAccessIT extends AbstractDaemonTest {
 
+  @Inject private GroupOperations groupOperations;
+
   private Project.NameKey normalProject;
   private Project.NameKey secretProject;
   private Project.NameKey secretRefProject;
   private TestAccount privilegedUser;
-  private InternalGroup privilegedGroup;
 
   @Before
   public void setUp() throws Exception {
     normalProject = createProject("normal");
     secretProject = createProject("secret");
     secretRefProject = createProject("secretRef");
-    privilegedGroup = group(createGroup("privilegedGroup"));
+    AccountGroup.UUID privilegedGroupUuid =
+        groupOperations.newGroup().name(name("privilegedGroup")).create();
 
     privilegedUser = accountCreator.create("privilegedUser", "snowden@nsa.gov", "Ed Snowden");
-    gApi.groups().id(privilegedGroup.getGroupUUID().get()).addMembers(privilegedUser.username);
+    groupOperations.group(privilegedGroupUuid).forUpdate().addMember(privilegedUser.id).update();
 
-    assertThat(gApi.groups().id(privilegedGroup.getGroupUUID().get()).members().get(0).email)
-        .contains("snowden");
-
-    grant(secretProject, "refs/*", Permission.READ, false, privilegedGroup.getGroupUUID());
+    grant(secretProject, "refs/*", Permission.READ, false, privilegedGroupUuid);
     block(secretProject, "refs/*", Permission.READ, SystemGroupBackend.REGISTERED_USERS);
 
     deny(secretRefProject, "refs/*", Permission.READ, SystemGroupBackend.ANONYMOUS_USERS);
-    grant(
-        secretRefProject,
-        "refs/heads/secret/*",
-        Permission.READ,
-        false,
-        privilegedGroup.getGroupUUID());
+    grant(secretRefProject, "refs/heads/secret/*", Permission.READ, false, privilegedGroupUuid);
     block(
         secretRefProject,
         "refs/heads/secret/*",
@@ -81,13 +77,8 @@
         SystemGroupBackend.REGISTERED_USERS);
 
     // Ref permission
-    grant(
-        normalProject,
-        "refs/*",
-        Permission.VIEW_PRIVATE_CHANGES,
-        false,
-        privilegedGroup.getGroupUUID());
-    grant(normalProject, "refs/*", Permission.FORGE_SERVER, false, privilegedGroup.getGroupUUID());
+    grant(normalProject, "refs/*", Permission.VIEW_PRIVATE_CHANGES, false, privilegedGroupUuid);
+    grant(normalProject, "refs/*", Permission.FORGE_SERVER, false, privilegedGroupUuid);
   }
 
   @Test
diff --git a/javatests/com/google/gerrit/acceptance/testsuite/group/GroupOperationsImplTest.java b/javatests/com/google/gerrit/acceptance/testsuite/group/GroupOperationsImplTest.java
new file mode 100644
index 0000000..954b0e6
--- /dev/null
+++ b/javatests/com/google/gerrit/acceptance/testsuite/group/GroupOperationsImplTest.java
@@ -0,0 +1,656 @@
+// Copyright (C) 2018 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.acceptance.testsuite.group;
+
+import static com.google.common.truth.Truth.assertThat;
+import static com.google.common.truth.Truth8.assertThat;
+
+import com.google.common.collect.ImmutableSet;
+import com.google.common.truth.Correspondence;
+import com.google.gerrit.acceptance.AbstractDaemonTest;
+import com.google.gerrit.acceptance.testsuite.account.AccountOperations;
+import com.google.gerrit.extensions.api.groups.GroupInput;
+import com.google.gerrit.extensions.common.AccountInfo;
+import com.google.gerrit.extensions.common.GroupInfo;
+import com.google.gerrit.extensions.restapi.RestApiException;
+import com.google.gerrit.reviewdb.client.Account;
+import com.google.gerrit.reviewdb.client.AccountGroup;
+import com.google.inject.Inject;
+import java.sql.Timestamp;
+import java.util.Objects;
+import java.util.Optional;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+
+public class GroupOperationsImplTest extends AbstractDaemonTest {
+
+  @Rule public ExpectedException expectedException = ExpectedException.none();
+
+  @Inject private AccountOperations accountOperations;
+
+  @Inject private GroupOperationsImpl groupOperations;
+
+  private int uniqueGroupNameIndex;
+
+  @Test
+  public void groupCanBeCreatedWithoutSpecifyingAnyParameters() throws Exception {
+    AccountGroup.UUID groupUuid = groupOperations.newGroup().create();
+
+    GroupInfo foundGroup = getGroupFromServer(groupUuid);
+    assertThat(foundGroup.id).isEqualTo(groupUuid.get());
+    assertThat(foundGroup.name).isNotEmpty();
+  }
+
+  @Test
+  public void twoGroupsWithoutAnyParametersDoNotClash() throws Exception {
+    AccountGroup.UUID groupUuid1 = groupOperations.newGroup().create();
+    AccountGroup.UUID groupUuid2 = groupOperations.newGroup().create();
+
+    TestGroup group1 = groupOperations.group(groupUuid1).get();
+    TestGroup group2 = groupOperations.group(groupUuid2).get();
+    assertThat(group1.groupUuid()).isNotEqualTo(group2.groupUuid());
+  }
+
+  @Test
+  public void groupCreatedByTestApiCanBeRetrievedViaOfficialApi() throws Exception {
+    AccountGroup.UUID groupUuid =
+        groupOperations.newGroup().name("unique group created via test API").create();
+
+    GroupInfo foundGroup = getGroupFromServer(groupUuid);
+    assertThat(foundGroup.id).isEqualTo(groupUuid.get());
+    assertThat(foundGroup.name).isEqualTo("unique group created via test API");
+  }
+
+  @Test
+  public void specifiedNameIsRespectedForGroupCreation() throws Exception {
+    AccountGroup.UUID groupUuid =
+        groupOperations.newGroup().name("XYZ-123-this-name-must-be-unique").create();
+
+    GroupInfo group = getGroupFromServer(groupUuid);
+    assertThat(group.name).isEqualTo("XYZ-123-this-name-must-be-unique");
+  }
+
+  @Test
+  public void specifiedDescriptionIsRespectedForGroupCreation() throws Exception {
+    AccountGroup.UUID groupUuid =
+        groupOperations.newGroup().description("All authenticated users").create();
+
+    GroupInfo group = getGroupFromServer(groupUuid);
+    assertThat(group.description).isEqualTo("All authenticated users");
+  }
+
+  @Test
+  public void requestingNoDescriptionIsPossibleForGroupCreation() throws Exception {
+    AccountGroup.UUID groupUuid = groupOperations.newGroup().clearDescription().create();
+
+    GroupInfo group = getGroupFromServer(groupUuid);
+    assertThat(group.description).isNull();
+  }
+
+  @Test
+  public void specifiedOwnerIsRespectedForGroupCreation() throws Exception {
+    AccountGroup.UUID ownerGroupUuid = groupOperations.newGroup().create();
+
+    AccountGroup.UUID groupUuid =
+        groupOperations.newGroup().ownerGroupUuid(ownerGroupUuid).create();
+
+    GroupInfo foundGroup = getGroupFromServer(groupUuid);
+    assertThat(foundGroup.ownerId).isEqualTo(ownerGroupUuid.get());
+  }
+
+  @Test
+  public void specifiedVisibilityIsRespectedForGroupCreation() throws Exception {
+    AccountGroup.UUID group1Uuid = groupOperations.newGroup().visibleToAll(true).create();
+    AccountGroup.UUID group2Uuid = groupOperations.newGroup().visibleToAll(false).create();
+
+    GroupInfo foundGroup1 = getGroupFromServer(group1Uuid);
+    GroupInfo foundGroup2 = getGroupFromServer(group2Uuid);
+    assertThat(foundGroup1.options.visibleToAll).isTrue();
+    // False == null
+    assertThat(foundGroup2.options.visibleToAll).isNull();
+  }
+
+  @Test
+  public void specifiedMembersAreRespectedForGroupCreation() throws Exception {
+    Account.Id account1Id = accountOperations.newAccount().create();
+    Account.Id account2Id = accountOperations.newAccount().create();
+    Account.Id account3Id = accountOperations.newAccount().create();
+    Account.Id account4Id = accountOperations.newAccount().create();
+
+    AccountGroup.UUID groupUuid =
+        groupOperations
+            .newGroup()
+            .members(account1Id, account2Id)
+            .addMember(account3Id)
+            .addMember(account4Id)
+            .create();
+
+    GroupInfo foundGroup = getGroupFromServer(groupUuid);
+    assertThat(foundGroup.members)
+        .comparingElementsUsing(getAccountToIdCorrespondence())
+        .containsExactly(account1Id, account2Id, account3Id, account4Id);
+  }
+
+  @Test
+  public void directlyAddingMembersIsPossibleForGroupCreation() throws Exception {
+    Account.Id account1Id = accountOperations.newAccount().create();
+    Account.Id account2Id = accountOperations.newAccount().create();
+
+    AccountGroup.UUID groupUuid =
+        groupOperations.newGroup().addMember(account1Id).addMember(account2Id).create();
+
+    GroupInfo foundGroup = getGroupFromServer(groupUuid);
+    assertThat(foundGroup.members)
+        .comparingElementsUsing(getAccountToIdCorrespondence())
+        .containsExactly(account1Id, account2Id);
+  }
+
+  @Test
+  public void requestingNoMembersIsPossibleForGroupCreation() throws Exception {
+    AccountGroup.UUID groupUuid = groupOperations.newGroup().clearMembers().create();
+
+    GroupInfo foundGroup = getGroupFromServer(groupUuid);
+    assertThat(foundGroup.members).isEmpty();
+  }
+
+  @Test
+  public void specifiedSubgroupsAreRespectedForGroupCreation() throws Exception {
+    AccountGroup.UUID group1Uuid = groupOperations.newGroup().create();
+    AccountGroup.UUID group2Uuid = groupOperations.newGroup().create();
+    AccountGroup.UUID group3Uuid = groupOperations.newGroup().create();
+    AccountGroup.UUID group4Uuid = groupOperations.newGroup().create();
+
+    AccountGroup.UUID groupUuid =
+        groupOperations
+            .newGroup()
+            .subgroups(group1Uuid, group2Uuid)
+            .addSubgroup(group3Uuid)
+            .addSubgroup(group4Uuid)
+            .create();
+
+    GroupInfo foundGroup = getGroupFromServer(groupUuid);
+    assertThat(foundGroup.includes)
+        .comparingElementsUsing(getGroupToUuidCorrespondence())
+        .containsExactly(group1Uuid, group2Uuid, group3Uuid, group4Uuid);
+  }
+
+  @Test
+  public void directlyAddingSubgroupsIsPossibleForGroupCreation() throws Exception {
+    AccountGroup.UUID group1Uuid = groupOperations.newGroup().create();
+    AccountGroup.UUID group2Uuid = groupOperations.newGroup().create();
+
+    AccountGroup.UUID groupUuid =
+        groupOperations.newGroup().addSubgroup(group1Uuid).addSubgroup(group2Uuid).create();
+
+    GroupInfo foundGroup = getGroupFromServer(groupUuid);
+    assertThat(foundGroup.includes)
+        .comparingElementsUsing(getGroupToUuidCorrespondence())
+        .containsExactly(group1Uuid, group2Uuid);
+  }
+
+  @Test
+  public void requestingNoSubgroupsIsPossibleForGroupCreation() throws Exception {
+    AccountGroup.UUID groupUuid = groupOperations.newGroup().clearSubgroups().create();
+
+    GroupInfo foundGroup = getGroupFromServer(groupUuid);
+    assertThat(foundGroup.includes).isEmpty();
+  }
+
+  @Test
+  public void existingGroupCanBeCheckedForExistence() throws Exception {
+    AccountGroup.UUID groupUuid = createGroupInServer(createArbitraryGroupInput());
+
+    boolean exists = groupOperations.group(groupUuid).exists();
+
+    assertThat(exists).isTrue();
+  }
+
+  @Test
+  public void notExistingGroupCanBeCheckedForExistence() throws Exception {
+    AccountGroup.UUID notExistingGroupUuid = new AccountGroup.UUID("not-existing-group");
+
+    boolean exists = groupOperations.group(notExistingGroupUuid).exists();
+
+    assertThat(exists).isFalse();
+  }
+
+  @Test
+  public void retrievingNotExistingGroupFails() throws Exception {
+    AccountGroup.UUID notExistingGroupUuid = new AccountGroup.UUID("not-existing-group");
+
+    expectedException.expect(IllegalStateException.class);
+    groupOperations.group(notExistingGroupUuid).get();
+  }
+
+  @Test
+  public void groupNotCreatedByTestApiCanBeRetrieved() throws Exception {
+    GroupInput input = createArbitraryGroupInput();
+    input.name = "unique group not created via test API";
+    AccountGroup.UUID groupUuid = createGroupInServer(input);
+
+    TestGroup foundGroup = groupOperations.group(groupUuid).get();
+
+    assertThat(foundGroup.groupUuid()).isEqualTo(groupUuid);
+    assertThat(foundGroup.name()).isEqualTo("unique group not created via test API");
+  }
+
+  @Test
+  public void uuidOfExistingGroupCanBeRetrieved() throws Exception {
+    AccountGroup.UUID groupUuid = groupOperations.newGroup().create();
+
+    AccountGroup.UUID foundGroupUuid = groupOperations.group(groupUuid).get().groupUuid();
+
+    assertThat(foundGroupUuid).isEqualTo(groupUuid);
+  }
+
+  @Test
+  public void nameOfExistingGroupCanBeRetrieved() throws Exception {
+    AccountGroup.UUID groupUuid =
+        groupOperations.newGroup().name("ABC-789-this-name-must-be-unique").create();
+
+    String groupName = groupOperations.group(groupUuid).get().name();
+
+    assertThat(groupName).isEqualTo("ABC-789-this-name-must-be-unique");
+  }
+
+  @Test
+  public void nameKeyOfExistingGroupCanBeRetrieved() throws Exception {
+    AccountGroup.UUID groupUuid =
+        groupOperations.newGroup().name("ABC-789-this-name-must-be-unique").create();
+
+    AccountGroup.NameKey groupName = groupOperations.group(groupUuid).get().nameKey();
+
+    assertThat(groupName).isEqualTo(new AccountGroup.NameKey("ABC-789-this-name-must-be-unique"));
+  }
+
+  @Test
+  public void descriptionOfExistingGroupCanBeRetrieved() throws Exception {
+    AccountGroup.UUID groupUuid =
+        groupOperations
+            .newGroup()
+            .description("This is a very detailed description of this group.")
+            .create();
+
+    Optional<String> description = groupOperations.group(groupUuid).get().description();
+
+    assertThat(description).hasValue("This is a very detailed description of this group.");
+  }
+
+  @Test
+  public void emptyDescriptionOfExistingGroupCanBeRetrieved() throws Exception {
+    AccountGroup.UUID groupUuid = groupOperations.newGroup().clearDescription().create();
+
+    Optional<String> description = groupOperations.group(groupUuid).get().description();
+
+    assertThat(description).isEmpty();
+  }
+
+  @Test
+  public void ownerGroupUuidOfExistingGroupCanBeRetrieved() throws Exception {
+    AccountGroup.UUID originalOwnerGroupUuid = new AccountGroup.UUID("owner group");
+    AccountGroup.UUID groupUuid =
+        groupOperations.newGroup().ownerGroupUuid(originalOwnerGroupUuid).create();
+
+    AccountGroup.UUID ownerGroupUuid = groupOperations.group(groupUuid).get().ownerGroupUuid();
+
+    assertThat(ownerGroupUuid).isEqualTo(originalOwnerGroupUuid);
+  }
+
+  @Test
+  public void visibilityOfExistingGroupCanBeRetrieved() throws Exception {
+    AccountGroup.UUID visibleGroupUuid = groupOperations.newGroup().visibleToAll(true).create();
+    AccountGroup.UUID invisibleGroupUuid = groupOperations.newGroup().visibleToAll(false).create();
+
+    TestGroup visibleGroup = groupOperations.group(visibleGroupUuid).get();
+    TestGroup invisibleGroup = groupOperations.group(invisibleGroupUuid).get();
+
+    assertThat(visibleGroup.visibleToAll()).named("visibility of visible group").isTrue();
+    assertThat(invisibleGroup.visibleToAll()).named("visibility of invisible group").isFalse();
+  }
+
+  @Test
+  public void createdOnOfExistingGroupCanBeRetrieved() throws Exception {
+    GroupInfo group = gApi.groups().create(createArbitraryGroupInput()).detail();
+    AccountGroup.UUID groupUuid = new AccountGroup.UUID(group.id);
+
+    Timestamp createdOn = groupOperations.group(groupUuid).get().createdOn();
+
+    assertThat(createdOn).isEqualTo(group.createdOn);
+  }
+
+  @Test
+  public void membersOfExistingGroupCanBeRetrieved() throws Exception {
+    Account.Id memberId1 = new Account.Id(1000);
+    Account.Id memberId2 = new Account.Id(2000);
+    Account.Id memberId3 = new Account.Id(3000);
+    AccountGroup.UUID groupUuid =
+        groupOperations.newGroup().members(memberId1, memberId2, memberId3).create();
+
+    ImmutableSet<Account.Id> members = groupOperations.group(groupUuid).get().members();
+
+    assertThat(members).containsExactly(memberId1, memberId2, memberId3);
+  }
+
+  @Test
+  public void emptyMembersOfExistingGroupCanBeRetrieved() throws Exception {
+    AccountGroup.UUID groupUuid = groupOperations.newGroup().clearMembers().create();
+
+    ImmutableSet<Account.Id> members = groupOperations.group(groupUuid).get().members();
+
+    assertThat(members).isEmpty();
+  }
+
+  @Test
+  public void subgroupsOfExistingGroupCanBeRetrieved() throws Exception {
+    AccountGroup.UUID subgroupUuid1 = new AccountGroup.UUID("subgroup 1");
+    AccountGroup.UUID subgroupUuid2 = new AccountGroup.UUID("subgroup 2");
+    AccountGroup.UUID subgroupUuid3 = new AccountGroup.UUID("subgroup 3");
+    AccountGroup.UUID groupUuid =
+        groupOperations.newGroup().subgroups(subgroupUuid1, subgroupUuid2, subgroupUuid3).create();
+
+    ImmutableSet<AccountGroup.UUID> subgroups = groupOperations.group(groupUuid).get().subgroups();
+
+    assertThat(subgroups).containsExactly(subgroupUuid1, subgroupUuid2, subgroupUuid3);
+  }
+
+  @Test
+  public void emptySubgroupsOfExistingGroupCanBeRetrieved() throws Exception {
+    AccountGroup.UUID groupUuid = groupOperations.newGroup().clearSubgroups().create();
+
+    ImmutableSet<AccountGroup.UUID> subgroups = groupOperations.group(groupUuid).get().subgroups();
+
+    assertThat(subgroups).isEmpty();
+  }
+
+  @Test
+  public void updateWithoutAnyParametersIsANoop() throws Exception {
+    AccountGroup.UUID groupUuid = groupOperations.newGroup().create();
+    TestGroup originalGroup = groupOperations.group(groupUuid).get();
+
+    groupOperations.group(groupUuid).forUpdate().update();
+
+    TestGroup updatedGroup = groupOperations.group(groupUuid).get();
+    assertThat(updatedGroup).isEqualTo(originalGroup);
+  }
+
+  @Test
+  public void updateWritesToInternalGroupSystem() throws Exception {
+    AccountGroup.UUID groupUuid =
+        groupOperations.newGroup().description("original description").create();
+
+    groupOperations.group(groupUuid).forUpdate().description("updated description").update();
+
+    String currentDescription = getGroupFromServer(groupUuid).description;
+    assertThat(currentDescription).isEqualTo("updated description");
+  }
+
+  @Test
+  public void nameCanBeUpdated() throws Exception {
+    AccountGroup.UUID groupUuid = groupOperations.newGroup().name("original name").create();
+
+    groupOperations.group(groupUuid).forUpdate().name("updated name").update();
+
+    String currentName = groupOperations.group(groupUuid).get().name();
+    assertThat(currentName).isEqualTo("updated name");
+  }
+
+  @Test
+  public void descriptionCanBeUpdated() throws Exception {
+    AccountGroup.UUID groupUuid =
+        groupOperations.newGroup().description("original description").create();
+
+    groupOperations.group(groupUuid).forUpdate().description("updated description").update();
+
+    Optional<String> currentDescription = groupOperations.group(groupUuid).get().description();
+    assertThat(currentDescription).hasValue("updated description");
+  }
+
+  @Test
+  public void descriptionCanBeCleared() throws Exception {
+    AccountGroup.UUID groupUuid =
+        groupOperations.newGroup().description("original description").create();
+
+    groupOperations.group(groupUuid).forUpdate().clearDescription().update();
+
+    Optional<String> currentDescription = groupOperations.group(groupUuid).get().description();
+    assertThat(currentDescription).isEmpty();
+  }
+
+  @Test
+  public void ownerGroupUuidCanBeUpdated() throws Exception {
+    AccountGroup.UUID originalOwnerGroupUuid = new AccountGroup.UUID("original owner");
+    AccountGroup.UUID groupUuid =
+        groupOperations.newGroup().ownerGroupUuid(originalOwnerGroupUuid).create();
+
+    AccountGroup.UUID updatedOwnerGroupUuid = new AccountGroup.UUID("updated owner");
+    groupOperations.group(groupUuid).forUpdate().ownerGroupUuid(updatedOwnerGroupUuid).update();
+
+    AccountGroup.UUID currentOwnerGroupUuid =
+        groupOperations.group(groupUuid).get().ownerGroupUuid();
+    assertThat(currentOwnerGroupUuid).isEqualTo(updatedOwnerGroupUuid);
+  }
+
+  @Test
+  public void visibilityCanBeUpdated() throws Exception {
+    AccountGroup.UUID groupUuid = groupOperations.newGroup().visibleToAll(true).create();
+
+    groupOperations.group(groupUuid).forUpdate().visibleToAll(false).update();
+
+    boolean visibleToAll = groupOperations.group(groupUuid).get().visibleToAll();
+    assertThat(visibleToAll).isFalse();
+  }
+
+  @Test
+  public void membersCanBeAdded() throws Exception {
+    AccountGroup.UUID groupUuid = groupOperations.newGroup().clearMembers().create();
+
+    Account.Id memberId1 = new Account.Id(1000);
+    Account.Id memberId2 = new Account.Id(2000);
+    groupOperations.group(groupUuid).forUpdate().addMember(memberId1).addMember(memberId2).update();
+
+    ImmutableSet<Account.Id> members = groupOperations.group(groupUuid).get().members();
+    assertThat(members).containsExactly(memberId1, memberId2);
+  }
+
+  @Test
+  public void membersCanBeRemoved() throws Exception {
+    Account.Id memberId1 = new Account.Id(1000);
+    Account.Id memberId2 = new Account.Id(2000);
+    AccountGroup.UUID groupUuid = groupOperations.newGroup().members(memberId1, memberId2).create();
+
+    groupOperations.group(groupUuid).forUpdate().removeMember(memberId2).update();
+
+    ImmutableSet<Account.Id> members = groupOperations.group(groupUuid).get().members();
+    assertThat(members).containsExactly(memberId1);
+  }
+
+  @Test
+  public void memberAdditionAndRemovalCanBeMixed() throws Exception {
+    Account.Id memberId1 = new Account.Id(1000);
+    Account.Id memberId2 = new Account.Id(2000);
+    AccountGroup.UUID groupUuid = groupOperations.newGroup().members(memberId1, memberId2).create();
+
+    Account.Id memberId3 = new Account.Id(3000);
+    groupOperations
+        .group(groupUuid)
+        .forUpdate()
+        .removeMember(memberId1)
+        .addMember(memberId3)
+        .update();
+
+    ImmutableSet<Account.Id> members = groupOperations.group(groupUuid).get().members();
+    assertThat(members).containsExactly(memberId2, memberId3);
+  }
+
+  @Test
+  public void membersCanBeCleared() throws Exception {
+    Account.Id memberId1 = new Account.Id(1000);
+    Account.Id memberId2 = new Account.Id(2000);
+    AccountGroup.UUID groupUuid = groupOperations.newGroup().members(memberId1, memberId2).create();
+
+    groupOperations.group(groupUuid).forUpdate().clearMembers().update();
+
+    ImmutableSet<Account.Id> members = groupOperations.group(groupUuid).get().members();
+    assertThat(members).isEmpty();
+  }
+
+  @Test
+  public void furtherMembersCanBeAddedAfterClearingAll() throws Exception {
+    Account.Id memberId1 = new Account.Id(1000);
+    Account.Id memberId2 = new Account.Id(2000);
+    AccountGroup.UUID groupUuid = groupOperations.newGroup().members(memberId1, memberId2).create();
+
+    Account.Id memberId3 = new Account.Id(3000);
+    groupOperations.group(groupUuid).forUpdate().clearMembers().addMember(memberId3).update();
+
+    ImmutableSet<Account.Id> members = groupOperations.group(groupUuid).get().members();
+    assertThat(members).containsExactly(memberId3);
+  }
+
+  @Test
+  public void subgroupsCanBeAdded() throws Exception {
+    AccountGroup.UUID groupUuid = groupOperations.newGroup().clearSubgroups().create();
+
+    AccountGroup.UUID subgroupUuid1 = new AccountGroup.UUID("subgroup 1");
+    AccountGroup.UUID subgroupUuid2 = new AccountGroup.UUID("subgroup 2");
+    groupOperations
+        .group(groupUuid)
+        .forUpdate()
+        .addSubgroup(subgroupUuid1)
+        .addSubgroup(subgroupUuid2)
+        .update();
+
+    ImmutableSet<AccountGroup.UUID> subgroups = groupOperations.group(groupUuid).get().subgroups();
+    assertThat(subgroups).containsExactly(subgroupUuid1, subgroupUuid2);
+  }
+
+  @Test
+  public void subgroupsCanBeRemoved() throws Exception {
+    AccountGroup.UUID subgroupUuid1 = new AccountGroup.UUID("subgroup 1");
+    AccountGroup.UUID subgroupUuid2 = new AccountGroup.UUID("subgroup 2");
+    AccountGroup.UUID groupUuid =
+        groupOperations.newGroup().subgroups(subgroupUuid1, subgroupUuid2).create();
+
+    groupOperations.group(groupUuid).forUpdate().removeSubgroup(subgroupUuid2).update();
+
+    ImmutableSet<AccountGroup.UUID> subgroups = groupOperations.group(groupUuid).get().subgroups();
+    assertThat(subgroups).containsExactly(subgroupUuid1);
+  }
+
+  @Test
+  public void subgroupAdditionAndRemovalCanBeMixed() throws Exception {
+    AccountGroup.UUID subgroupUuid1 = new AccountGroup.UUID("subgroup 1");
+    AccountGroup.UUID subgroupUuid2 = new AccountGroup.UUID("subgroup 2");
+    AccountGroup.UUID groupUuid =
+        groupOperations.newGroup().subgroups(subgroupUuid1, subgroupUuid2).create();
+
+    AccountGroup.UUID subgroupUuid3 = new AccountGroup.UUID("subgroup 3");
+    groupOperations
+        .group(groupUuid)
+        .forUpdate()
+        .removeSubgroup(subgroupUuid1)
+        .addSubgroup(subgroupUuid3)
+        .update();
+
+    ImmutableSet<AccountGroup.UUID> subgroups = groupOperations.group(groupUuid).get().subgroups();
+    assertThat(subgroups).containsExactly(subgroupUuid2, subgroupUuid3);
+  }
+
+  @Test
+  public void subgroupsCanBeCleared() throws Exception {
+    AccountGroup.UUID subgroupUuid1 = new AccountGroup.UUID("subgroup 1");
+    AccountGroup.UUID subgroupUuid2 = new AccountGroup.UUID("subgroup 2");
+    AccountGroup.UUID groupUuid =
+        groupOperations.newGroup().subgroups(subgroupUuid1, subgroupUuid2).create();
+
+    groupOperations.group(groupUuid).forUpdate().clearSubgroups().update();
+
+    ImmutableSet<AccountGroup.UUID> subgroups = groupOperations.group(groupUuid).get().subgroups();
+    assertThat(subgroups).isEmpty();
+  }
+
+  @Test
+  public void furtherSubgroupsCanBeAddedAfterClearingAll() throws Exception {
+    AccountGroup.UUID subgroupUuid1 = new AccountGroup.UUID("subgroup 1");
+    AccountGroup.UUID subgroupUuid2 = new AccountGroup.UUID("subgroup 2");
+    AccountGroup.UUID groupUuid =
+        groupOperations.newGroup().subgroups(subgroupUuid1, subgroupUuid2).create();
+
+    AccountGroup.UUID subgroupUuid3 = new AccountGroup.UUID("subgroup 3");
+    groupOperations
+        .group(groupUuid)
+        .forUpdate()
+        .clearSubgroups()
+        .addSubgroup(subgroupUuid3)
+        .update();
+
+    ImmutableSet<AccountGroup.UUID> subgroups = groupOperations.group(groupUuid).get().subgroups();
+    assertThat(subgroups).containsExactly(subgroupUuid3);
+  }
+
+  private GroupInput createArbitraryGroupInput() {
+    GroupInput groupInput = new GroupInput();
+    groupInput.name = name("verifiers-" + uniqueGroupNameIndex++);
+    return groupInput;
+  }
+
+  private GroupInfo getGroupFromServer(AccountGroup.UUID groupUuid) throws RestApiException {
+    return gApi.groups().id(groupUuid.get()).detail();
+  }
+
+  private AccountGroup.UUID createGroupInServer(GroupInput input) throws RestApiException {
+    GroupInfo group = gApi.groups().create(input).detail();
+    return new AccountGroup.UUID(group.id);
+  }
+
+  private static Correspondence<AccountInfo, Account.Id> getAccountToIdCorrespondence() {
+    return new Correspondence<AccountInfo, Account.Id>() {
+      @Override
+      public boolean compare(AccountInfo actualAccount, Account.Id expectedId) {
+        Account.Id accountId =
+            Optional.ofNullable(actualAccount)
+                .map(account -> account._accountId)
+                .map(Account.Id::new)
+                .orElse(null);
+        return Objects.equals(accountId, expectedId);
+      }
+
+      @Override
+      public String toString() {
+        return "has ID";
+      }
+    };
+  }
+
+  private static Correspondence<GroupInfo, AccountGroup.UUID> getGroupToUuidCorrespondence() {
+    return new Correspondence<GroupInfo, AccountGroup.UUID>() {
+      @Override
+      public boolean compare(GroupInfo actualGroup, AccountGroup.UUID expectedUuid) {
+        AccountGroup.UUID groupUuid =
+            Optional.ofNullable(actualGroup)
+                .map(group -> group.id)
+                .map(AccountGroup.UUID::new)
+                .orElse(null);
+        return Objects.equals(groupUuid, expectedUuid);
+      }
+
+      @Override
+      public String toString() {
+        return "has UUID";
+      }
+    };
+  }
+}