ONOS-3655 - Adding Junit tests for DeviceKey subsystem, and adding DeviceKey
event, listener, store and delegate classes.  DeviceKeyManager and store
implementation will be added in the next submission.

Change-Id: I60edb1753e9ee2985ccabc2b6ec9c223867590de
diff --git a/incubator/api/src/test/java/org/onosproject/incubator/net/key/DeviceKeyIdTest.java b/incubator/api/src/test/java/org/onosproject/incubator/net/key/DeviceKeyIdTest.java
new file mode 100644
index 0000000..5f6c477
--- /dev/null
+++ b/incubator/api/src/test/java/org/onosproject/incubator/net/key/DeviceKeyIdTest.java
@@ -0,0 +1,75 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.incubator.net.key;
+
+import com.google.common.testing.EqualsTester;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.onlab.junit.ImmutableClassChecker.assertThatClassIsImmutable;
+
+/**
+ * Test class for DeviceDeyId.
+ */
+public class DeviceKeyIdTest {
+
+    final String deviceKeyIdValue1 = "DeviceKeyId1";
+    final String deviceKeyIdValue2 = "DeviceKeyId2";
+
+    /**
+     * Checks that the DeviceKeyId class is immutable.
+     */
+    @Test
+    public void testImmutability() {
+        assertThatClassIsImmutable(DeviceKeyId.class);
+    }
+
+    /**
+     * Checks the construction of a DeviceKeyId object throws an
+     * IllegalArgumentException when the input identifier is null.
+     */
+    @Test(expected = NullPointerException.class)
+    public void testConstructionUsingNullId() {
+        DeviceKeyId.deviceKeyId(null);
+    }
+
+    /**
+     * Checks the construction of a DeviceKeyId object.
+     */
+    @Test
+    public void testConstruction() {
+        DeviceKeyId deviceKeyId = DeviceKeyId.deviceKeyId(deviceKeyIdValue1);
+        assertNotNull("The deviceKeyId should not be null.", deviceKeyId);
+        assertEquals("The id should match the expected value.",
+                     deviceKeyIdValue1, deviceKeyId.id());
+    }
+
+    /**
+     * Tests the equality of device key identifiers.
+     */
+    @Test
+    public void testEquality() {
+        DeviceKeyId deviceKeyId1 = DeviceKeyId.deviceKeyId(deviceKeyIdValue1);
+        DeviceKeyId deviceKeyId2 = DeviceKeyId.deviceKeyId(deviceKeyIdValue1);
+        DeviceKeyId deviceKeyId3 = DeviceKeyId.deviceKeyId(deviceKeyIdValue2);
+
+        new EqualsTester().addEqualityGroup(deviceKeyId1, deviceKeyId2)
+                .addEqualityGroup(deviceKeyId3)
+                .testEquals();
+    }
+}