Add CLI command to view provisioned subscribers

Change-Id: I67a49d7fa569e9f4f28eb8eaea1b34ba2bd5a5fa
diff --git a/api/src/main/java/org/onosproject/olt/AccessDeviceService.java b/api/src/main/java/org/onosproject/olt/AccessDeviceService.java
index 74d8a28..456e264 100644
--- a/api/src/main/java/org/onosproject/olt/AccessDeviceService.java
+++ b/api/src/main/java/org/onosproject/olt/AccessDeviceService.java
@@ -21,6 +21,7 @@
 import org.onosproject.net.ConnectPoint;
 import org.onosproject.net.DeviceId;
 
+import java.util.Collection;
 import java.util.Map;
 
 /**
@@ -45,6 +46,13 @@
     void removeSubscriber(ConnectPoint port);
 
     /**
+     * Returns information about the provisioned subscribers.
+     *
+     * @return subscribers
+     */
+    Collection<Map.Entry<ConnectPoint, VlanId>> getSubscribers();
+
+    /**
      * Returns the map of configured OLTs.
      *
      * @return a map