[ONOS-2159]Add to query devices by type api in DeviceService and
DeviceStore interfaces

Change-Id: Ifa7e94e08eb150fb4d71248a50a390832d1549df
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 88c2f94..539fd5f 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
@@ -19,6 +19,7 @@
 import com.google.common.collect.FluentIterable;
 
 import org.onosproject.net.Device;
+import org.onosproject.net.Device.Type;
 import org.onosproject.net.DeviceId;
 import org.onosproject.net.MastershipRole;
 import org.onosproject.net.Port;
@@ -91,4 +92,14 @@
     public void removeListener(DeviceListener listener) {
     }
 
+    @Override
+    public Iterable<Device> getDevices(Type type) {
+        return Collections.emptyList();
+    }
+
+    @Override
+    public Iterable<Device> getAvailableDevices(Type type) {
+        return Collections.emptyList();
+    }
+
 }