diff --git a/src/main/java/com/googlesource/gerrit/plugins/its/base/its/ItsConfig.java b/src/main/java/com/googlesource/gerrit/plugins/its/base/its/ItsConfig.java
index 46cfe92..1a803e9 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/its/base/its/ItsConfig.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/its/base/its/ItsConfig.java
@@ -64,25 +64,25 @@
   public boolean isEnabled(Event event) {
     if (event instanceof PatchSetCreatedEvent) {
       PatchSetCreatedEvent e = (PatchSetCreatedEvent) event;
-      return isEnabled(e.change.project, e.getRefName());
+      return isEnabled(e.getProjectNameKey().get(), e.getRefName());
     } else if (event instanceof CommentAddedEvent) {
       CommentAddedEvent e = (CommentAddedEvent) event;
-      return isEnabled(e.change.project, e.getRefName());
+      return isEnabled(e.getProjectNameKey().get(), e.getRefName());
     } else if (event instanceof ChangeMergedEvent) {
       ChangeMergedEvent e = (ChangeMergedEvent) event;
-      return isEnabled(e.change.project, e.getRefName());
+      return isEnabled(e.getProjectNameKey().get(), e.getRefName());
     } else if (event instanceof ChangeAbandonedEvent) {
       ChangeAbandonedEvent e = (ChangeAbandonedEvent) event;
-      return isEnabled(e.change.project, e.getRefName());
+      return isEnabled(e.getProjectNameKey().get(), e.getRefName());
     } else if (event instanceof ChangeRestoredEvent) {
       ChangeRestoredEvent e = (ChangeRestoredEvent) event;
-      return isEnabled(e.change.project, e.getRefName());
+      return isEnabled(e.getProjectNameKey().get(), e.getRefName());
     } else if (event instanceof DraftPublishedEvent) {
       DraftPublishedEvent e = (DraftPublishedEvent) event;
-      return isEnabled(e.change.project, e.getRefName());
+      return isEnabled(e.getProjectNameKey().get(), e.getRefName());
     } else if (event instanceof RefUpdatedEvent) {
       RefUpdatedEvent e = (RefUpdatedEvent) event;
-      return isEnabled(e.refUpdate.project, e.refUpdate.refName);
+      return isEnabled(e.getProjectNameKey().get(), e.refUpdate.get().refName);
     } else {
       log.debug("Event " + event + " not recognised and ignored");
       return false;
diff --git a/src/main/java/com/googlesource/gerrit/plugins/its/base/util/PropertyExtractor.java b/src/main/java/com/googlesource/gerrit/plugins/its/base/util/PropertyExtractor.java
index 55d5a8d..8c30a0c 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/its/base/util/PropertyExtractor.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/its/base/util/PropertyExtractor.java
@@ -75,91 +75,91 @@
   private Map<String,Set<String>> extractFrom(ChangeAbandonedEvent event,
       Set<Property> common) {
     common.add(propertyFactory.create("event-type", event.type));
-    common.addAll(propertyAttributeExtractor.extractFrom(event.change));
-    common.addAll(propertyAttributeExtractor.extractFrom(event.abandoner, "abandoner"));
-    common.addAll(propertyAttributeExtractor.extractFrom(event.patchSet));
+    common.addAll(propertyAttributeExtractor.extractFrom(event.change.get()));
+    common.addAll(propertyAttributeExtractor.extractFrom(event.abandoner.get(), "abandoner"));
+    common.addAll(propertyAttributeExtractor.extractFrom(event.patchSet.get()));
     common.add(propertyFactory.create("reason", event.reason));
-    PatchSet.Id patchSetId = newPatchSetId(event.change.number,
-        event.patchSet.number);
-    return issueExtractor.getIssueIds(event.change.project,
-        event.patchSet.revision, patchSetId);
+    PatchSet.Id patchSetId = newPatchSetId(event.change.get().number,
+        event.patchSet.get().number);
+    return issueExtractor.getIssueIds(event.change.get().project,
+        event.patchSet.get().revision, patchSetId);
   }
 
   private Map<String,Set<String>> extractFrom(ChangeMergedEvent event,
       Set<Property> common) {
     common.add(propertyFactory.create("event-type", event.type));
-    common.addAll(propertyAttributeExtractor.extractFrom(event.change));
-    common.addAll(propertyAttributeExtractor.extractFrom(event.submitter, "submitter"));
-    common.addAll(propertyAttributeExtractor.extractFrom(event.patchSet));
-    PatchSet.Id patchSetId = newPatchSetId(event.change.number,
-        event.patchSet.number);
-    return issueExtractor.getIssueIds(event.change.project,
-        event.patchSet.revision, patchSetId);
+    common.addAll(propertyAttributeExtractor.extractFrom(event.change.get()));
+    common.addAll(propertyAttributeExtractor.extractFrom(event.submitter.get(), "submitter"));
+    common.addAll(propertyAttributeExtractor.extractFrom(event.patchSet.get()));
+    PatchSet.Id patchSetId = newPatchSetId(event.change.get().number,
+        event.patchSet.get().number);
+    return issueExtractor.getIssueIds(event.change.get().project,
+        event.patchSet.get().revision, patchSetId);
   }
 
   private Map<String,Set<String>> extractFrom(ChangeRestoredEvent event,
       Set<Property> common) {
     common.add(propertyFactory.create("event-type", event.type));
-    common.addAll(propertyAttributeExtractor.extractFrom(event.change));
-    common.addAll(propertyAttributeExtractor.extractFrom(event.restorer, "restorer"));
-    common.addAll(propertyAttributeExtractor.extractFrom(event.patchSet));
+    common.addAll(propertyAttributeExtractor.extractFrom(event.change.get()));
+    common.addAll(propertyAttributeExtractor.extractFrom(event.restorer.get(), "restorer"));
+    common.addAll(propertyAttributeExtractor.extractFrom(event.patchSet.get()));
     common.add(propertyFactory.create("reason", event.reason));
-    PatchSet.Id patchSetId = newPatchSetId(event.change.number,
-        event.patchSet.number);
-    return issueExtractor.getIssueIds(event.change.project,
-        event.patchSet.revision, patchSetId);
+    PatchSet.Id patchSetId = newPatchSetId(event.change.get().number,
+        event.patchSet.get().number);
+    return issueExtractor.getIssueIds(event.change.get().project,
+        event.patchSet.get().revision, patchSetId);
   }
 
   private Map<String,Set<String>> extractFrom(DraftPublishedEvent event,
       Set<Property> common) {
     common.add(propertyFactory.create("event-type", event.type));
-    common.addAll(propertyAttributeExtractor.extractFrom(event.change));
-    common.addAll(propertyAttributeExtractor.extractFrom(event.patchSet));
-    common.addAll(propertyAttributeExtractor.extractFrom(event.uploader, "uploader"));
-    PatchSet.Id patchSetId = newPatchSetId(event.change.number,
-        event.patchSet.number);
-    return issueExtractor.getIssueIds(event.change.project,
-        event.patchSet.revision, patchSetId);
+    common.addAll(propertyAttributeExtractor.extractFrom(event.change.get()));
+    common.addAll(propertyAttributeExtractor.extractFrom(event.patchSet.get()));
+    common.addAll(propertyAttributeExtractor.extractFrom(event.uploader.get(), "uploader"));
+    PatchSet.Id patchSetId = newPatchSetId(event.change.get().number,
+        event.patchSet.get().number);
+    return issueExtractor.getIssueIds(event.change.get().project,
+        event.patchSet.get().revision, patchSetId);
   }
 
   private Map<String,Set<String>> extractFrom(RefUpdatedEvent event,
       Set<Property> common) {
     common.add(propertyFactory.create("event-type", event.type));
-    common.addAll(propertyAttributeExtractor.extractFrom(event.submitter, "submitter"));
-    common.addAll(propertyAttributeExtractor.extractFrom(event.refUpdate));
-    return issueExtractor.getIssueIds(event.refUpdate.project,
-        event.refUpdate.newRev);
+    common.addAll(propertyAttributeExtractor.extractFrom(event.submitter.get(), "submitter"));
+    common.addAll(propertyAttributeExtractor.extractFrom(event.refUpdate.get()));
+    return issueExtractor.getIssueIds(event.refUpdate.get().project,
+        event.refUpdate.get().newRev);
   }
 
   private Map<String,Set<String>> extractFrom(PatchSetCreatedEvent event,
       Set<Property> common) {
     common.add(propertyFactory.create("event-type", event.type));
-    common.addAll(propertyAttributeExtractor.extractFrom(event.change));
-    common.addAll(propertyAttributeExtractor.extractFrom(event.patchSet));
-    common.addAll(propertyAttributeExtractor.extractFrom(event.uploader, "uploader"));
-    PatchSet.Id patchSetId = newPatchSetId(event.change.number,
-        event.patchSet.number);
-    return issueExtractor.getIssueIds(event.change.project,
-        event.patchSet.revision, patchSetId);
+    common.addAll(propertyAttributeExtractor.extractFrom(event.change.get()));
+    common.addAll(propertyAttributeExtractor.extractFrom(event.patchSet.get()));
+    common.addAll(propertyAttributeExtractor.extractFrom(event.uploader.get(), "uploader"));
+    PatchSet.Id patchSetId = newPatchSetId(event.change.get().number,
+        event.patchSet.get().number);
+    return issueExtractor.getIssueIds(event.change.get().project,
+        event.patchSet.get().revision, patchSetId);
   }
 
   private Map<String,Set<String>> extractFrom(CommentAddedEvent event,
       Set<Property> common) {
     common.add(propertyFactory.create("event-type", event.type));
-    common.addAll(propertyAttributeExtractor.extractFrom(event.change));
-    common.addAll(propertyAttributeExtractor.extractFrom(event.patchSet));
-    common.addAll(propertyAttributeExtractor.extractFrom(event.author, "commenter"));
+    common.addAll(propertyAttributeExtractor.extractFrom(event.change.get()));
+    common.addAll(propertyAttributeExtractor.extractFrom(event.patchSet.get()));
+    common.addAll(propertyAttributeExtractor.extractFrom(event.author.get(), "commenter"));
     if (event.approvals != null) {
-      for (ApprovalAttribute approvalAttribute : event.approvals) {
+      for (ApprovalAttribute approvalAttribute : event.approvals.get()) {
         common.addAll(propertyAttributeExtractor.extractFrom(
             approvalAttribute));
       }
     }
     common.add(propertyFactory.create("comment", event.comment));
-    PatchSet.Id patchSetId = newPatchSetId(event.change.number,
-        event.patchSet.number);
-    return issueExtractor.getIssueIds(event.change.project,
-        event.patchSet.revision, patchSetId);
+    PatchSet.Id patchSetId = newPatchSetId(event.change.get().number,
+        event.patchSet.get().number);
+    return issueExtractor.getIssueIds(event.change.get().project,
+        event.patchSet.get().revision, patchSetId);
   }
 
   /**
diff --git a/src/test/java/com/googlesource/gerrit/plugins/its/base/its/ItsConfigTest.java b/src/test/java/com/googlesource/gerrit/plugins/its/base/its/ItsConfigTest.java
index 32c3f20..678bc76 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/its/base/its/ItsConfigTest.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/its/base/its/ItsConfigTest.java
@@ -16,6 +16,7 @@
 
 import static org.easymock.EasyMock.expect;
 
+import com.google.common.base.Suppliers;
 import com.google.gerrit.extensions.annotations.PluginName;
 import com.google.gerrit.extensions.config.FactoryModule;
 import com.google.gerrit.reviewdb.client.Project;
@@ -277,9 +278,10 @@
     setupIsEnabled("true", null, branches);
 
     PatchSetCreatedEvent event = new PatchSetCreatedEvent();
-    event.change = new ChangeAttribute();
-    event.change.project = "testProject";
-    event.change.branch = "testBranch";
+    ChangeAttribute changeAttribute = new ChangeAttribute();
+    changeAttribute.project = "testProject";
+    changeAttribute.branch = "testBranch";
+    event.change = Suppliers.ofInstance(changeAttribute);
 
     ItsConfig itsConfig = createItsConfig();
 
@@ -293,9 +295,10 @@
     setupIsEnabled("true", null, branches);
 
     PatchSetCreatedEvent event = new PatchSetCreatedEvent();
-    event.change = new ChangeAttribute();
-    event.change.project = "testProject";
-    event.change.branch = "testBranch";
+    ChangeAttribute changeAttribute = new ChangeAttribute();
+    changeAttribute.project = "testProject";
+    changeAttribute.branch = "testBranch";
+    event.change = Suppliers.ofInstance(changeAttribute);
 
     ItsConfig itsConfig = createItsConfig();
 
@@ -309,9 +312,10 @@
     setupIsEnabled("true", null, branches);
 
     PatchSetCreatedEvent event = new PatchSetCreatedEvent();
-    event.change = new ChangeAttribute();
-    event.change.project = "testProject";
-    event.change.branch = "testBranch";
+    ChangeAttribute changeAttribute = new ChangeAttribute();
+    changeAttribute.project = "testProject";
+    changeAttribute.branch = "testBranch";
+    event.change = Suppliers.ofInstance(changeAttribute);
 
     ItsConfig itsConfig = createItsConfig();
 
@@ -325,9 +329,10 @@
     setupIsEnabled("true", null, branches);
 
     PatchSetCreatedEvent event = new PatchSetCreatedEvent();
-    event.change = new ChangeAttribute();
-    event.change.project = "testProject";
-    event.change.branch = "testBranch";
+    ChangeAttribute changeAttribute = new ChangeAttribute();
+    changeAttribute.project = "testProject";
+    changeAttribute.branch = "testBranch";
+    event.change = Suppliers.ofInstance(changeAttribute);
 
     ItsConfig itsConfig = createItsConfig();
 
@@ -341,9 +346,10 @@
     setupIsEnabled("true", null, branches);
 
     PatchSetCreatedEvent event = new PatchSetCreatedEvent();
-    event.change = new ChangeAttribute();
-    event.change.project = "testProject";
-    event.change.branch = "testBranch";
+    ChangeAttribute changeAttribute = new ChangeAttribute();
+    changeAttribute.project = "testProject";
+    changeAttribute.branch = "testBranch";
+    event.change = Suppliers.ofInstance(changeAttribute);
 
     ItsConfig itsConfig = createItsConfig();
 
@@ -357,9 +363,10 @@
     setupIsEnabled("true", null, branches);
 
     PatchSetCreatedEvent event = new PatchSetCreatedEvent();
-    event.change = new ChangeAttribute();
-    event.change.project = "testProject";
-    event.change.branch = "testBranch";
+    ChangeAttribute changeAttribute = new ChangeAttribute();
+    changeAttribute.project = "testProject";
+    changeAttribute.branch = "testBranch";
+    event.change = Suppliers.ofInstance(changeAttribute);
 
     ItsConfig itsConfig = createItsConfig();
 
@@ -373,9 +380,10 @@
     setupIsEnabled("true", null, branches);
 
     PatchSetCreatedEvent event = new PatchSetCreatedEvent();
-    event.change = new ChangeAttribute();
-    event.change.project = "testProject";
-    event.change.branch = "testBranch";
+    ChangeAttribute changeAttribute = new ChangeAttribute();
+    changeAttribute.project = "testProject";
+    changeAttribute.branch = "testBranch";
+    event.change = Suppliers.ofInstance(changeAttribute);
 
     ItsConfig itsConfig = createItsConfig();
 
@@ -389,9 +397,10 @@
     setupIsEnabled("true", null, branches);
 
     PatchSetCreatedEvent event = new PatchSetCreatedEvent();
-    event.change = new ChangeAttribute();
-    event.change.project = "testProject";
-    event.change.branch = "testBranch";
+    ChangeAttribute changeAttribute = new ChangeAttribute();
+    changeAttribute.project = "testProject";
+    changeAttribute.branch = "testBranch";
+    event.change = Suppliers.ofInstance(changeAttribute);
 
     ItsConfig itsConfig = createItsConfig();
 
@@ -405,9 +414,10 @@
     setupIsEnabled("false", null, branches);
 
     PatchSetCreatedEvent event = new PatchSetCreatedEvent();
-    event.change = new ChangeAttribute();
-    event.change.project = "testProject";
-    event.change.branch = "testBranch";
+    ChangeAttribute changeAttribute = new ChangeAttribute();
+    changeAttribute.project = "testProject";
+    changeAttribute.branch = "testBranch";
+    event.change = Suppliers.ofInstance(changeAttribute);
 
     ItsConfig itsConfig = createItsConfig();
 
@@ -421,9 +431,10 @@
     setupIsEnabled("true", null, branches);
 
     CommentAddedEvent event = new CommentAddedEvent();
-    event.change = new ChangeAttribute();
-    event.change.project = "testProject";
-    event.change.branch = "testBranch";
+    ChangeAttribute changeAttribute = new ChangeAttribute();
+    changeAttribute.project = "testProject";
+    changeAttribute.branch = "testBranch";
+    event.change = Suppliers.ofInstance(changeAttribute);
 
     ItsConfig itsConfig = createItsConfig();
 
@@ -437,9 +448,10 @@
     setupIsEnabled("true", null, branches);
 
     ChangeMergedEvent event = new ChangeMergedEvent();
-    event.change = new ChangeAttribute();
-    event.change.project = "testProject";
-    event.change.branch = "testBranch";
+    ChangeAttribute changeAttribute = new ChangeAttribute();
+    changeAttribute.project = "testProject";
+    changeAttribute.branch = "testBranch";
+    event.change = Suppliers.ofInstance(changeAttribute);
 
     ItsConfig itsConfig = createItsConfig();
 
@@ -453,9 +465,10 @@
     setupIsEnabled("true", null, branches);
 
     ChangeAbandonedEvent event = new ChangeAbandonedEvent();
-    event.change = new ChangeAttribute();
-    event.change.project = "testProject";
-    event.change.branch = "testBranch";
+    ChangeAttribute changeAttribute = new ChangeAttribute();
+    changeAttribute.project = "testProject";
+    changeAttribute.branch = "testBranch";
+    event.change = Suppliers.ofInstance(changeAttribute);
 
     ItsConfig itsConfig = createItsConfig();
 
@@ -469,9 +482,10 @@
     setupIsEnabled("true", null, branches);
 
     ChangeRestoredEvent event = new ChangeRestoredEvent();
-    event.change = new ChangeAttribute();
-    event.change.project = "testProject";
-    event.change.branch = "testBranch";
+    ChangeAttribute changeAttribute = new ChangeAttribute();
+    changeAttribute.project = "testProject";
+    changeAttribute.branch = "testBranch";
+    event.change = Suppliers.ofInstance(changeAttribute);
 
     ItsConfig itsConfig = createItsConfig();
 
@@ -485,9 +499,10 @@
     setupIsEnabled("true", null, branches);
 
     DraftPublishedEvent event = new DraftPublishedEvent();
-    event.change = new ChangeAttribute();
-    event.change.project = "testProject";
-    event.change.branch = "testBranch";
+    ChangeAttribute changeAttribute = new ChangeAttribute();
+    changeAttribute.project = "testProject";
+    changeAttribute.branch = "testBranch";
+    event.change = Suppliers.ofInstance(changeAttribute);
 
     ItsConfig itsConfig = createItsConfig();
 
@@ -501,9 +516,11 @@
     setupIsEnabled("true", null, branches);
 
     RefUpdatedEvent event = new RefUpdatedEvent();
-    event.refUpdate = new RefUpdateAttribute();
-    event.refUpdate.project = "testProject";
-    event.refUpdate.refName = "refs/heads/testBranch";
+
+    RefUpdateAttribute refUpdate = new RefUpdateAttribute();
+    refUpdate.project = "testProject";
+    refUpdate.refName = "refs/heads/testBranch";
+    event.refUpdate = Suppliers.ofInstance(refUpdate);
 
     ItsConfig itsConfig = createItsConfig();
 
diff --git a/src/test/java/com/googlesource/gerrit/plugins/its/base/util/PropertyExtractorTest.java b/src/test/java/com/googlesource/gerrit/plugins/its/base/util/PropertyExtractorTest.java
index de432bb..90d379a 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/its/base/util/PropertyExtractorTest.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/its/base/util/PropertyExtractorTest.java
@@ -15,6 +15,7 @@
 
 import static org.easymock.EasyMock.expect;
 
+import com.google.common.base.Suppliers;
 import com.google.common.collect.Maps;
 import com.google.common.collect.Sets;
 import com.google.gerrit.extensions.annotations.PluginName;
@@ -72,19 +73,19 @@
     ChangeAbandonedEvent event = new ChangeAbandonedEvent();
 
     ChangeAttribute changeAttribute = createMock(ChangeAttribute.class);
-    event.change = changeAttribute;
+    event.change = Suppliers.ofInstance(changeAttribute);
     Property propertyChange = createMock(Property.class);
     expect(propertyAttributeExtractor.extractFrom(changeAttribute))
         .andReturn(Sets.newHashSet(propertyChange));
 
     AccountAttribute accountAttribute = createMock(AccountAttribute.class);
-    event.abandoner= accountAttribute;
+    event.abandoner= Suppliers.ofInstance(accountAttribute);
     Property propertySubmitter = createMock(Property.class);
     expect(propertyAttributeExtractor.extractFrom(accountAttribute,
         "abandoner")).andReturn(Sets.newHashSet(propertySubmitter));
 
     PatchSetAttribute patchSetAttribute = createMock(PatchSetAttribute.class);
-    event.patchSet = patchSetAttribute;
+    event.patchSet = Suppliers.ofInstance(patchSetAttribute);
     Property propertyPatchSet = createMock(Property.class);
     expect(propertyAttributeExtractor.extractFrom(patchSetAttribute))
         .andReturn(Sets.newHashSet(propertyPatchSet));
@@ -113,19 +114,19 @@
     ChangeMergedEvent event = new ChangeMergedEvent();
 
     ChangeAttribute changeAttribute = createMock(ChangeAttribute.class);
-    event.change = changeAttribute;
+    event.change = Suppliers.ofInstance(changeAttribute);
     Property propertyChange = createMock(Property.class);
     expect(propertyAttributeExtractor.extractFrom(changeAttribute))
         .andReturn(Sets.newHashSet(propertyChange));
 
     AccountAttribute accountAttribute = createMock(AccountAttribute.class);
-    event.submitter = accountAttribute;
+    event.submitter = Suppliers.ofInstance(accountAttribute);
     Property propertySubmitter = createMock(Property.class);
     expect(propertyAttributeExtractor.extractFrom(accountAttribute,
         "submitter")).andReturn(Sets.newHashSet(propertySubmitter));
 
     PatchSetAttribute patchSetAttribute = createMock(PatchSetAttribute.class);
-    event.patchSet = patchSetAttribute;
+    event.patchSet = Suppliers.ofInstance(patchSetAttribute);
     Property propertyPatchSet = createMock(Property.class);
     expect(propertyAttributeExtractor.extractFrom(patchSetAttribute))
         .andReturn(Sets.newHashSet(propertyPatchSet));
@@ -147,19 +148,19 @@
     ChangeRestoredEvent event = new ChangeRestoredEvent();
 
     ChangeAttribute changeAttribute = createMock(ChangeAttribute.class);
-    event.change = changeAttribute;
+    event.change = Suppliers.ofInstance(changeAttribute);
     Property propertyChange = createMock(Property.class);
     expect(propertyAttributeExtractor.extractFrom(changeAttribute))
         .andReturn(Sets.newHashSet(propertyChange));
 
     AccountAttribute accountAttribute = createMock(AccountAttribute.class);
-    event.restorer = accountAttribute;
+    event.restorer = Suppliers.ofInstance(accountAttribute);
     Property propertySubmitter = createMock(Property.class);
     expect(propertyAttributeExtractor.extractFrom(accountAttribute,
         "restorer")).andReturn(Sets.newHashSet(propertySubmitter));
 
     PatchSetAttribute patchSetAttribute = createMock(PatchSetAttribute.class);
-    event.patchSet = patchSetAttribute;
+    event.patchSet = Suppliers.ofInstance(patchSetAttribute);
     Property propertyPatchSet = createMock(Property.class);
     expect(propertyAttributeExtractor.extractFrom(patchSetAttribute))
         .andReturn(Sets.newHashSet(propertyPatchSet));
@@ -187,19 +188,19 @@
     CommentAddedEvent event = new CommentAddedEvent();
 
     ChangeAttribute changeAttribute = createMock(ChangeAttribute.class);
-    event.change = changeAttribute;
+    event.change = Suppliers.ofInstance(changeAttribute);
     Property propertyChange = createMock(Property.class);
     expect(propertyAttributeExtractor.extractFrom(changeAttribute))
         .andReturn(Sets.newHashSet(propertyChange));
 
     AccountAttribute accountAttribute = createMock(AccountAttribute.class);
-    event.author = accountAttribute;
+    event.author = Suppliers.ofInstance(accountAttribute);
     Property propertySubmitter = createMock(Property.class);
     expect(propertyAttributeExtractor.extractFrom(accountAttribute,
         "commenter")).andReturn(Sets.newHashSet(propertySubmitter));
 
     PatchSetAttribute patchSetAttribute = createMock(PatchSetAttribute.class);
-    event.patchSet = patchSetAttribute;
+    event.patchSet = Suppliers.ofInstance(patchSetAttribute);
     Property propertyPatchSet = createMock(Property.class);
     expect(propertyAttributeExtractor.extractFrom(patchSetAttribute))
         .andReturn(Sets.newHashSet(propertyPatchSet));
@@ -227,19 +228,19 @@
     CommentAddedEvent event = new CommentAddedEvent();
 
     ChangeAttribute changeAttribute = createMock(ChangeAttribute.class);
-    event.change = changeAttribute;
+    event.change = Suppliers.ofInstance(changeAttribute);
     Property propertyChange = createMock(Property.class);
     expect(propertyAttributeExtractor.extractFrom(changeAttribute))
         .andReturn(Sets.newHashSet(propertyChange));
 
     AccountAttribute accountAttribute = createMock(AccountAttribute.class);
-    event.author = accountAttribute;
+    event.author = Suppliers.ofInstance(accountAttribute);
     Property propertySubmitter = createMock(Property.class);
     expect(propertyAttributeExtractor.extractFrom(accountAttribute,
         "commenter")).andReturn(Sets.newHashSet(propertySubmitter));
 
     PatchSetAttribute patchSetAttribute = createMock(PatchSetAttribute.class);
-    event.patchSet = patchSetAttribute;
+    event.patchSet = Suppliers.ofInstance(patchSetAttribute);
     Property propertyPatchSet = createMock(Property.class);
     expect(propertyAttributeExtractor.extractFrom(patchSetAttribute))
         .andReturn(Sets.newHashSet(propertyPatchSet));
@@ -254,7 +255,7 @@
         .andReturn(Sets.newHashSet(propertyApproval2));
     ApprovalAttribute approvalAttributes[] = { approvalAttribute1,
         approvalAttribute2 };
-    event.approvals = approvalAttributes;
+    event.approvals = Suppliers.ofInstance(approvalAttributes);
 
     event.comment = "testComment";
     Property propertyComment = createMock(Property.class);
@@ -281,19 +282,19 @@
     DraftPublishedEvent event = new DraftPublishedEvent();
 
     ChangeAttribute changeAttribute = createMock(ChangeAttribute.class);
-    event.change = changeAttribute;
+    event.change = Suppliers.ofInstance(changeAttribute);
     Property propertyChange = createMock(Property.class);
     expect(propertyAttributeExtractor.extractFrom(changeAttribute))
         .andReturn(Sets.newHashSet(propertyChange));
 
     AccountAttribute accountAttribute = createMock(AccountAttribute.class);
-    event.uploader = accountAttribute;
+    event.uploader = Suppliers.ofInstance(accountAttribute);
     Property propertySubmitter = createMock(Property.class);
     expect(propertyAttributeExtractor.extractFrom(accountAttribute,
         "uploader")).andReturn(Sets.newHashSet(propertySubmitter));
 
     PatchSetAttribute patchSetAttribute = createMock(PatchSetAttribute.class);
-    event.patchSet = patchSetAttribute;
+    event.patchSet = Suppliers.ofInstance(patchSetAttribute);
     Property propertyPatchSet = createMock(Property.class);
     expect(propertyAttributeExtractor.extractFrom(patchSetAttribute))
         .andReturn(Sets.newHashSet(propertyPatchSet));
@@ -316,19 +317,19 @@
     PatchSetCreatedEvent event = new PatchSetCreatedEvent();
 
     ChangeAttribute changeAttribute = createMock(ChangeAttribute.class);
-    event.change = changeAttribute;
+    event.change = Suppliers.ofInstance(changeAttribute);
     Property propertyChange = createMock(Property.class);
     expect(propertyAttributeExtractor.extractFrom(changeAttribute))
         .andReturn(Sets.newHashSet(propertyChange));
 
     AccountAttribute accountAttribute = createMock(AccountAttribute.class);
-    event.uploader = accountAttribute;
+    event.uploader = Suppliers.ofInstance(accountAttribute);
     Property propertySubmitter = createMock(Property.class);
     expect(propertyAttributeExtractor.extractFrom(accountAttribute,
         "uploader")).andReturn(Sets.newHashSet(propertySubmitter));
 
     PatchSetAttribute patchSetAttribute = createMock(PatchSetAttribute.class);
-    event.patchSet = patchSetAttribute;
+    event.patchSet = Suppliers.ofInstance(patchSetAttribute);
     Property propertyPatchSet = createMock(Property.class);
     expect(propertyAttributeExtractor.extractFrom(patchSetAttribute))
         .andReturn(Sets.newHashSet(propertyPatchSet));
@@ -351,14 +352,14 @@
     RefUpdatedEvent event = new RefUpdatedEvent();
 
     AccountAttribute accountAttribute = createMock(AccountAttribute.class);
-    event.submitter = accountAttribute;
+    event.submitter = Suppliers.ofInstance(accountAttribute);
     Property propertySubmitter = createMock(Property.class);
     expect(propertyAttributeExtractor.extractFrom(accountAttribute,
         "submitter")).andReturn(Sets.newHashSet(propertySubmitter));
 
     RefUpdateAttribute refUpdateAttribute =
         createMock(RefUpdateAttribute.class);
-    event.refUpdate = refUpdateAttribute;
+    event.refUpdate = Suppliers.ofInstance(refUpdateAttribute);
     Property propertyRefUpdated = createMock(Property.class);
     expect(propertyAttributeExtractor.extractFrom(refUpdateAttribute))
         .andReturn(Sets.newHashSet(propertyRefUpdated));