Delta Port Statistics added to DeviceStore, Device Service and CLI
Changed misspelled word in description of the portstats command switch

Change-Id: I131940c83c5cb12080532a4804ec424ca66afa64
diff --git a/core/api/src/test/java/org/onosproject/net/device/DeviceServiceAdapter.java b/core/api/src/test/java/org/onosproject/net/device/DeviceServiceAdapter.java
index 539fd5f..795e4c0 100644
--- a/core/api/src/test/java/org/onosproject/net/device/DeviceServiceAdapter.java
+++ b/core/api/src/test/java/org/onosproject/net/device/DeviceServiceAdapter.java
@@ -75,6 +75,11 @@
     }
 
     @Override
+    public List<PortStatistics> getPortDeltaStatistics(DeviceId deviceId) {
+        return null;
+    }
+
+    @Override
     public Port getPort(DeviceId deviceId, PortNumber portNumber) {
         return null;
     }