diff --git a/java/com/google/gerrit/server/restapi/change/PostReviewAttentionSet.java b/java/com/google/gerrit/server/restapi/change/PostReviewAttentionSet.java
index 3541ef0..aeb2c2e 100644
--- a/java/com/google/gerrit/server/restapi/change/PostReviewAttentionSet.java
+++ b/java/com/google/gerrit/server/restapi/change/PostReviewAttentionSet.java
@@ -158,7 +158,7 @@
   private void processManualUpdates(BatchUpdate bu, RevisionResource revision, ReviewInput input)
       throws BadRequestException, IOException, PermissionBackendException,
           UnprocessableEntityException, ConfigInvalidException {
-    Set<Account.Id> accountsChangedInCommit = new HashSet();
+    Set<Account.Id> accountsChangedInCommit = new HashSet<>();
     // If we specify a user to remove, and the user is in the attention set, we remove it.
     if (input.removeFromAttentionSet != null) {
       for (AttentionSetInput remove : input.removeFromAttentionSet) {
diff --git a/javatests/com/google/gerrit/acceptance/api/accounts/AccountIT.java b/javatests/com/google/gerrit/acceptance/api/accounts/AccountIT.java
index 0cd6182..3c1bc2f 100644
--- a/javatests/com/google/gerrit/acceptance/api/accounts/AccountIT.java
+++ b/javatests/com/google/gerrit/acceptance/api/accounts/AccountIT.java
@@ -1221,7 +1221,7 @@
   @Test
   public void cannotAddNonConfirmedEmailWithoutModifyAccountPermission() throws Exception {
     TestAccount account = accountCreator.create(name("user"));
-    EmailInput input = newEmailInput("test@test.com");
+    EmailInput input = newEmailInput("test@example.com");
     requestScopeOperations.setApiUser(user.id());
     assertThrows(AuthException.class, () -> gApi.accounts().id(account.username()).addEmail(input));
   }
diff --git a/javatests/com/google/gerrit/acceptance/api/change/ChangeIT.java b/javatests/com/google/gerrit/acceptance/api/change/ChangeIT.java
index 744035e..39a860e 100644
--- a/javatests/com/google/gerrit/acceptance/api/change/ChangeIT.java
+++ b/javatests/com/google/gerrit/acceptance/api/change/ChangeIT.java
@@ -1878,7 +1878,7 @@
     Timestamp oldTs = rsrc.getChange().getLastUpdatedOn();
 
     // create a group named "ab" with one user: testUser
-    String email = "abcd@test.com";
+    String email = "abcd@example.com";
     String fullname = "abcd";
     Account.Id accountIdOfTestUser =
         accountOperations
@@ -1931,11 +1931,11 @@
     accountOperations
         .newAccount()
         .username("kobebryant")
-        .preferredEmail("kobebryant@test.com")
+        .preferredEmail("kobebryant@example.com")
         .fullname(testUserFullname)
         .create();
 
-    String myGroupUserEmail = "lee@test.com";
+    String myGroupUserEmail = "lee@example.com";
     String myGroupUserFullname = "lee";
     Account.Id accountIdOfGroupUser =
         accountOperations
@@ -3747,7 +3747,7 @@
             "Configure Notifications",
             "project.config",
             "[notify \"my=notify-config\"]\n"
-                + "  email = foo@test.com\n"
+                + "  email = foo@example.com\n"
                 + "  filter = dir:\\\"foo/bar/baz\\\"");
     push.to(RefNames.REFS_CONFIG);
     testRepo.reset(oldHead);
@@ -3759,7 +3759,8 @@
             admin.newIdent(), testRepo, "Test change", "foo/bar/baz/test.txt", "some content");
     PushOneCommit.Result r = push.to("refs/for/master");
     assertThat(sender.getMessages()).hasSize(1);
-    assertThat(sender.getMessages().get(0).rcpt()).containsExactly(Address.parse("foo@test.com"));
+    assertThat(sender.getMessages().get(0).rcpt())
+        .containsExactly(Address.parse("foo@example.com"));
 
     // Comment on the change.
     sender.clear();
@@ -3767,7 +3768,8 @@
     reviewInput.message = "some message";
     gApi.changes().id(r.getChangeId()).current().review(reviewInput);
     assertThat(sender.getMessages()).hasSize(1);
-    assertThat(sender.getMessages().get(0).rcpt()).containsExactly(Address.parse("foo@test.com"));
+    assertThat(sender.getMessages().get(0).rcpt())
+        .containsExactly(Address.parse("foo@example.com"));
   }
 
   @Test
diff --git a/javatests/com/google/gerrit/acceptance/rest/change/AttentionSetIT.java b/javatests/com/google/gerrit/acceptance/rest/change/AttentionSetIT.java
index 640109a..a8149ce 100644
--- a/javatests/com/google/gerrit/acceptance/rest/change/AttentionSetIT.java
+++ b/javatests/com/google/gerrit/acceptance/rest/change/AttentionSetIT.java
@@ -828,7 +828,7 @@
     change(r).addToAttentionSet(new AttentionSetInput(user.email(), "remove"));
 
     requestScopeOperations.setApiUser(user.id());
-    ReviewInput reviewInput = ReviewInput.create().recommend();
+    ReviewInput reviewInput = ReviewInput.recommend();
     change(r).current().review(reviewInput);
 
     // reviewer removed
diff --git a/javatests/com/google/gerrit/acceptance/server/project/ProjectWatchIT.java b/javatests/com/google/gerrit/acceptance/server/project/ProjectWatchIT.java
index 7a80cbd..a9114b9 100644
--- a/javatests/com/google/gerrit/acceptance/server/project/ProjectWatchIT.java
+++ b/javatests/com/google/gerrit/acceptance/server/project/ProjectWatchIT.java
@@ -279,7 +279,7 @@
     sender.clear();
 
     // watch project as user2
-    TestAccount user2 = accountCreator.create("user2", "user2@test.com", "User2", null);
+    TestAccount user2 = accountCreator.create("user2", "user2@example.com", "User2", null);
     requestScopeOperations.setApiUser(user2.id());
     watch(watchedProject);
 
@@ -391,7 +391,7 @@
     sender.clear();
 
     // watch project as user2
-    TestAccount user2 = accountCreator.create("user2", "user2@test.com", "User2", null);
+    TestAccount user2 = accountCreator.create("user2", "user2@example.com", "User2", null);
     requestScopeOperations.setApiUser(user2.id());
     watch(anyProject);
 
@@ -528,7 +528,7 @@
     // watch project as user that can view all private change
     TestAccount userThatCanViewPrivateChanges =
         accountCreator.create(
-            "user2", "user2@test.com", "User2", null, groupThatCanViewPrivateChanges.name);
+            "user2", "user2@example.com", "User2", null, groupThatCanViewPrivateChanges.name);
     requestScopeOperations.setApiUser(userThatCanViewPrivateChanges.id());
     watch(watchedProject);
 
diff --git a/javatests/com/google/gerrit/server/mail/send/FromAddressGeneratorProviderTest.java b/javatests/com/google/gerrit/server/mail/send/FromAddressGeneratorProviderTest.java
index a383d56..03129ae 100644
--- a/javatests/com/google/gerrit/server/mail/send/FromAddressGeneratorProviderTest.java
+++ b/javatests/com/google/gerrit/server/mail/send/FromAddressGeneratorProviderTest.java
@@ -146,9 +146,9 @@
   @Test
   public void USERNoAllowDomain() {
     setFrom("USER");
-    setDomains(Arrays.asList("example.com"));
+    setDomains(Arrays.asList("example.net"));
     final String name = "A U. Thor";
-    final String email = "a.u.thor@test.com";
+    final String email = "a.u.thor@example.com";
     final Account.Id user = user(name, email);
 
     final Address r = create().from(user);
@@ -161,10 +161,10 @@
   @Test
   public void USERAllowDomainTwice() {
     setFrom("USER");
+    setDomains(Arrays.asList("example.net"));
     setDomains(Arrays.asList("example.com"));
-    setDomains(Arrays.asList("test.com"));
     final String name = "A U. Thor";
-    final String email = "a.u.thor@test.com";
+    final String email = "a.u.thor@example.com";
     final Account.Id user = user(name, email);
 
     final Address r = create().from(user);
@@ -177,10 +177,10 @@
   @Test
   public void USERAllowDomainTwiceReverse() {
     setFrom("USER");
-    setDomains(Arrays.asList("test.com"));
     setDomains(Arrays.asList("example.com"));
+    setDomains(Arrays.asList("example.net"));
     final String name = "A U. Thor";
-    final String email = "a.u.thor@test.com";
+    final String email = "a.u.thor@example.com";
     final Account.Id user = user(name, email);
 
     final Address r = create().from(user);
@@ -193,9 +193,9 @@
   @Test
   public void USERAllowTwoDomains() {
     setFrom("USER");
-    setDomains(Arrays.asList("example.com", "test.com"));
+    setDomains(Arrays.asList("example.com", "example.net"));
     final String name = "A U. Thor";
-    final String email = "a.u.thor@test.com";
+    final String email = "a.u.thor@example.com";
     final Account.Id user = user(name, email);
 
     final Address r = create().from(user);
diff --git a/javatests/com/google/gerrit/server/query/account/AbstractQueryAccountsTest.java b/javatests/com/google/gerrit/server/query/account/AbstractQueryAccountsTest.java
index 59f2b6d..f5c9628 100644
--- a/javatests/com/google/gerrit/server/query/account/AbstractQueryAccountsTest.java
+++ b/javatests/com/google/gerrit/server/query/account/AbstractQueryAccountsTest.java
@@ -217,7 +217,7 @@
 
     AccountInfo user5 = newAccountWithEmail("user5", name("user5MixedCase@example.com"));
 
-    assertQuery("notexisting@test.com");
+    assertQuery("notexisting@example.com");
 
     assertQuery(currentUserInfo.email, currentUserInfo);
     assertQuery("email:" + currentUserInfo.email, currentUserInfo);
@@ -253,8 +253,8 @@
 
   @Test
   public void byEmailWithoutModifyAccountCapability() throws Exception {
-    String preferredEmail = name("primary@test.com");
-    String secondaryEmail = name("secondary@test.com");
+    String preferredEmail = name("primary@example.com");
+    String secondaryEmail = name("secondary@example.com");
     AccountInfo user1 = newAccountWithEmail("user1", preferredEmail);
     addEmails(user1, secondaryEmail);
 
@@ -485,11 +485,11 @@
     // sorting by account ID. Use the same fullname for all accounts so that sorting must be done by
     // preferred email.
     AccountInfo userFoo3 =
-        newAccount("user3", "foo-" + appendix, "foo3-" + appendix + "@test.com", true);
+        newAccount("user3", "foo-" + appendix, "foo3-" + appendix + "@example.com", true);
     AccountInfo userFoo1 =
-        newAccount("user1", "foo-" + appendix, "foo1-" + appendix + "@test.com", true);
+        newAccount("user1", "foo-" + appendix, "foo1-" + appendix + "@example.com", true);
     AccountInfo userFoo2 =
-        newAccount("user2", "foo-" + appendix, "foo2-" + appendix + "@test.com", true);
+        newAccount("user2", "foo-" + appendix, "foo2-" + appendix + "@example.com", true);
     assertThat(userFoo3._accountId).isLessThan(userFoo1._accountId);
     assertThat(userFoo1._accountId).isLessThan(userFoo2._accountId);