Starting work on virtual network subsystem implementation.

Change-Id: Ic702ce425d68fa5c1af5c6d55cad5940665ac562
diff --git a/incubator/api/src/main/java/org/onosproject/incubator/net/virtual/DefaultVirtualNetwork.java b/incubator/api/src/main/java/org/onosproject/incubator/net/virtual/DefaultVirtualNetwork.java
new file mode 100644
index 0000000..c114191
--- /dev/null
+++ b/incubator/api/src/main/java/org/onosproject/incubator/net/virtual/DefaultVirtualNetwork.java
@@ -0,0 +1,76 @@
+/*
+ * Copyright 2015 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.virtual;
+
+import java.util.Objects;
+
+import static com.google.common.base.MoreObjects.toStringHelper;
+
+/**
+ * Default implementation of the virtual network descriptor.
+ */
+public class DefaultVirtualNetwork implements VirtualNetwork {
+
+    private final NetworkId id;
+    private final TenantId tenantId;
+
+    /**
+     * Creates a new virtual network descriptor.
+     *
+     * @param id       network identifier
+     * @param tenantId tenant identifier
+     */
+    public DefaultVirtualNetwork(NetworkId id, TenantId tenantId) {
+        this.id = id;
+        this.tenantId = tenantId;
+    }
+
+    @Override
+    public NetworkId id() {
+        return id;
+    }
+
+    @Override
+    public TenantId tenantId() {
+        return tenantId;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(id, tenantId);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj instanceof DefaultVirtualNetwork) {
+            DefaultVirtualNetwork that = (DefaultVirtualNetwork) obj;
+            return Objects.equals(this.id, that.id)
+                    && Objects.equals(this.tenantId, that.tenantId);
+        }
+        return false;
+    }
+
+    @Override
+    public String toString() {
+        return toStringHelper(this)
+                .add("id", id)
+                .add("tenantId", tenantId)
+                .toString();
+    }
+}