Add base interface for virtualnetwork ps class

src/Network/Common/IVirtualNetworkLinkVirtualNetwork.cs

@@ -0,0 +1,22 @@
+// ----------------------------------------------------------------------------------
+//
+// Copyright Microsoft Corporation
+// 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.
+// ----------------------------------------------------------------------------------
+
+
+namespace Microsoft.Azure.Management.Internal.Network.Common
+{
+    public interface IVirtualNetworkLinkVirtualNetwork
+    {
+        string Id { get; set; }
+    }
+}