diff --git a/core/common/src/test/java/org/onosproject/store/trivial/SimpleDeviceStore.java b/core/common/src/test/java/org/onosproject/store/trivial/SimpleDeviceStore.java
index 04d376c..a3761b0 100644
--- a/core/common/src/test/java/org/onosproject/store/trivial/SimpleDeviceStore.java
+++ b/core/common/src/test/java/org/onosproject/store/trivial/SimpleDeviceStore.java
@@ -126,6 +126,11 @@
     }
 
     @Override
+    public int getAvailableDeviceCount() {
+        return availableDevices.size();
+    }
+
+    @Override
     public Iterable<Device> getDevices() {
         return Collections.unmodifiableCollection(devices.values());
     }
diff --git a/core/common/src/test/java/org/onosproject/store/trivial/SimpleDeviceStoreTest.java b/core/common/src/test/java/org/onosproject/store/trivial/SimpleDeviceStoreTest.java
index f8eb1ba..c4ceb18 100644
--- a/core/common/src/test/java/org/onosproject/store/trivial/SimpleDeviceStoreTest.java
+++ b/core/common/src/test/java/org/onosproject/store/trivial/SimpleDeviceStoreTest.java
@@ -156,6 +156,22 @@
     }
 
     @Test
+    public final void testGetAvailableDeviceCount() {
+        assertEquals("initialy empty", 0, deviceStore.getAvailableDeviceCount());
+
+        putDevice(DID1, SW1);
+        putDevice(DID2, SW2);
+
+        deviceStore.markOffline(DID1);
+
+        assertEquals("expect 1 available device", 1, deviceStore.getAvailableDeviceCount());
+
+        putDevice(DID1, SW1);
+
+        assertEquals("expect 2 available devices", 2, deviceStore.getAvailableDeviceCount());
+    }
+
+    @Test
     public final void testGetDevices() {
         assertEquals("initialy empty", 0, Iterables.size(deviceStore.getDevices()));