ONOS-1443: Group bucket statistics support and group CLI formatting

Change-Id: Iaa6d8ae1f9222eb9c29d14bf1615a7449e50c4d3
diff --git a/core/api/src/main/java/org/onosproject/net/group/GroupBuckets.java b/core/api/src/main/java/org/onosproject/net/group/GroupBuckets.java
index 26cd5f6..c0b5e5c 100644
--- a/core/api/src/main/java/org/onosproject/net/group/GroupBuckets.java
+++ b/core/api/src/main/java/org/onosproject/net/group/GroupBuckets.java
@@ -70,7 +70,7 @@
     @Override
     public String toString() {
         return toStringHelper(this)
-                .add("buckets", buckets)
+                .add("buckets", buckets.toString())
                 .toString();
     }
 }
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