CORD-13:Table Statistics support along with CLI and REST

Change-Id: Ic7facc73754c4b1e7c9c5a9eecd217f89a67e135
diff --git a/core/api/src/main/java/org/onosproject/net/flow/FlowRuleService.java b/core/api/src/main/java/org/onosproject/net/flow/FlowRuleService.java
index d4f959c..ee8d5a9 100644
--- a/core/api/src/main/java/org/onosproject/net/flow/FlowRuleService.java
+++ b/core/api/src/main/java/org/onosproject/net/flow/FlowRuleService.java
@@ -104,4 +104,11 @@
      */
     void apply(FlowRuleOperations ops);
 
+    /**
+     * Returns the collection of flow table statistics of the specified device.
+     *
+     * @param deviceId device identifier
+     * @return collection of flow table statistics
+     */
+    Iterable<TableStatisticsEntry> getFlowTableStatistics(DeviceId deviceId);
 }