diff --git a/apps/vtn/vtnrsc/src/main/java/org/onosproject/vtnrsc/PortPairId.java b/apps/vtn/vtnrsc/src/main/java/org/onosproject/vtnrsc/PortPairId.java
index 05c31aa..e14e95a 100644
--- a/apps/vtn/vtnrsc/src/main/java/org/onosproject/vtnrsc/PortPairId.java
+++ b/apps/vtn/vtnrsc/src/main/java/org/onosproject/vtnrsc/PortPairId.java
@@ -16,11 +16,9 @@
 package org.onosproject.vtnrsc;
 
 import static com.google.common.base.MoreObjects.toStringHelper;
-import static com.google.common.base.Preconditions.checkNotNull;
 
 import java.util.UUID;
-
-import com.google.common.base.Objects;
+import java.util.Objects;
 
 /**
  * Representation of a Port Pair ID.
@@ -34,8 +32,7 @@
      *
      * @param id UUID id of port pair
      */
-    private PortPairId(UUID id) {
-        checkNotNull(id, "Port chain id can not be null");
+    private PortPairId(final UUID id) {
         this.portPairId = id;
     }
 
@@ -45,7 +42,7 @@
      * @param id UUID of port pair id
      * @return object of port pair id
      */
-    public static PortPairId portPairId(UUID id) {
+    public static PortPairId portPairId(final UUID id) {
         return new PortPairId(id);
     }
 
@@ -55,7 +52,7 @@
      * @param id port pair id in string
      * @return object of port pair id
      */
-    public static PortPairId portPairId(String id) {
+    public static PortPairId portPairId(final String id) {
         return new PortPairId(UUID.fromString(id));
     }
 
@@ -73,10 +70,9 @@
         if (this == obj) {
             return true;
         }
-
-        if (obj.getClass()  == this.getClass()) {
-            PortPairId that = (PortPairId) obj;
-            return Objects.equal(this.portPairId, that.portPairId);
+        if (obj instanceof PortPairId) {
+            final PortPairId other = (PortPairId) obj;
+            return Objects.equals(this.portPairId, other.portPairId);
         }
         return false;
     }
@@ -88,8 +84,6 @@
 
     @Override
     public String toString() {
-        return toStringHelper(this)
-                .add("portPairId", portPairId.toString())
-                .toString();
+        return toStringHelper(this).add("portPairId", portPairId.toString()).toString();
     }
 }