Addressing review comments of patch-3
Addressing review comments of patch-2
Fixing javadoc warnings
Pushing changes for onos-5146 - Added 2 new APIs in DeviceService.java to get port specific PortStatistics by specifying Device ID & Port Number. Also implemented the APIs in SimpleDeviceStore etc. This will be a very useful API for app developers who are intersted to query port specific port statistics

Change-Id: I8f3e5a443eb5b50237a679999311b48609e54a44
diff --git a/incubator/net/src/main/java/org/onosproject/incubator/net/virtual/impl/VirtualNetworkDeviceService.java b/incubator/net/src/main/java/org/onosproject/incubator/net/virtual/impl/VirtualNetworkDeviceService.java
index 5dfdd57..c466502 100644
--- a/incubator/net/src/main/java/org/onosproject/incubator/net/virtual/impl/VirtualNetworkDeviceService.java
+++ b/incubator/net/src/main/java/org/onosproject/incubator/net/virtual/impl/VirtualNetworkDeviceService.java
@@ -47,6 +47,7 @@
     private static final String NETWORK_NULL = "Network ID cannot be null";
     private static final String TYPE_NULL = "Type cannot be null";
     private static final String DEVICE_NULL = "Device cannot be null";
+    private static final String PORT_NUMBER_NULL = "PortNumber cannot be null";
 
     private final VirtualNetwork network;
     private final VirtualNetworkService manager;
@@ -135,6 +136,22 @@
     }
 
     @Override
+    public PortStatistics getStatisticsForPort(DeviceId deviceId, PortNumber portNumber) {
+        checkNotNull(deviceId, DEVICE_NULL);
+        checkNotNull(deviceId, PORT_NUMBER_NULL);
+        // TODO not supported at the moment.
+        return null;
+    }
+
+    @Override
+    public PortStatistics getDeltaStatisticsForPort(DeviceId deviceId, PortNumber portNumber) {
+        checkNotNull(deviceId, DEVICE_NULL);
+        checkNotNull(deviceId, PORT_NUMBER_NULL);
+        // TODO not supported at the moment.
+        return null;
+    }
+
+    @Override
     public Port getPort(DeviceId deviceId, PortNumber portNumber) {
         checkNotNull(deviceId, DEVICE_NULL);