diff --git a/core/api/src/test/java/org/onosproject/store/service/TestDistributedSet.java b/core/api/src/test/java/org/onosproject/store/service/TestDistributedSet.java
index 79c108b..49f28f2 100644
--- a/core/api/src/test/java/org/onosproject/store/service/TestDistributedSet.java
+++ b/core/api/src/test/java/org/onosproject/store/service/TestDistributedSet.java
@@ -70,18 +70,24 @@
 
     @Override
     public CompletableFuture<Boolean> add(E element) {
-        SetEvent<E> event =
-                new SetEvent<>(setName, SetEvent.Type.ADD, element);
-        notifyListeners(event);
-        return CompletableFuture.completedFuture(set.add(element));
+        boolean updated = set.add(element);
+        if (updated) {
+            SetEvent<E> event =
+                    new SetEvent<>(setName, SetEvent.Type.ADD, element);
+            notifyListeners(event);
+        }
+        return CompletableFuture.completedFuture(updated);
     }
 
     @Override
     public CompletableFuture<Boolean> remove(E element) {
-        SetEvent<E> event =
-                new SetEvent<>(setName, SetEvent.Type.REMOVE, element);
-        notifyListeners(event);
-        return CompletableFuture.completedFuture(set.remove(element));
+        boolean updated = set.remove(element);
+        if (updated) {
+            SetEvent<E> event =
+                    new SetEvent<>(setName, SetEvent.Type.REMOVE, element);
+            notifyListeners(event);
+        }
+        return CompletableFuture.completedFuture(updated);
     }
 
     @Override
@@ -107,8 +113,10 @@
 
     @Override
     public CompletableFuture<Boolean> addAll(Collection<? extends E> c) {
-        c.forEach(this::add);
-        return CompletableFuture.completedFuture(true);
+        return c.stream()
+                .map(this::add)
+                .reduce(CompletableFuture.completedFuture(false),
+                        (l, r) -> l.thenCombine(r, Boolean::logicalOr));
     }
 
     @Override
@@ -118,15 +126,19 @@
 
     @Override
     public CompletableFuture<Boolean> retainAll(Collection<? extends E> c) {
-        Set notInSet2;
-        notInSet2 = Sets.difference(set, (Set<?>) c);
+        Set<? extends E> s = (c instanceof Set) ?
+                             (Set<? extends E>) c :
+                             ImmutableSet.copyOf(c);
+        Set<E> notInSet2 = Sets.difference(set, s);
         return removeAll(ImmutableSet.copyOf(notInSet2));
     }
 
     @Override
     public CompletableFuture<Boolean> removeAll(Collection<? extends E> c) {
-        c.forEach(this::remove);
-        return CompletableFuture.completedFuture(true);
+        return c.stream()
+                .map(this::remove)
+                .reduce(CompletableFuture.completedFuture(false),
+                        (l, r) -> l.thenCombine(r, Boolean::logicalOr));
     }
 
     @Override
@@ -154,8 +166,8 @@
      *
      * @return Builder
      **/
-    public static Builder builder() {
-        return new Builder();
+    public static <E> Builder<E> builder() {
+        return new Builder<>();
     }
 
     /**
@@ -166,7 +178,7 @@
     public static class Builder<E> extends DistributedSetBuilder<E> {
         @Override
         public AsyncDistributedSet<E> build() {
-            return new TestDistributedSet(name());
+            return new TestDistributedSet<>(name());
         }
     }
 }