Initial import of CFM and SOAM api

Change-Id: Icf5cc2d5fb34b75460e80e8cced0d70265bcd33b
diff --git a/incubator/api/src/main/java/org/onosproject/incubator/net/l2monitoring/cfm/service/MdEvent.java b/incubator/api/src/main/java/org/onosproject/incubator/net/l2monitoring/cfm/service/MdEvent.java
new file mode 100644
index 0000000..e3090f7
--- /dev/null
+++ b/incubator/api/src/main/java/org/onosproject/incubator/net/l2monitoring/cfm/service/MdEvent.java
@@ -0,0 +1,38 @@
+/*
+ * Copyright 2017-present Open Networking Foundation
+ *
+ * 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.l2monitoring.cfm.service;
+
+import org.onosproject.event.AbstractEvent;
+import org.onosproject.incubator.net.l2monitoring.cfm.identifier.MdId;
+
+/**
+ * Event related to the maintenance of CFM MDs.
+ */
+public class MdEvent extends AbstractEvent<MdEvent.Type, MdId> {
+
+    /**
+     * MD Event types supported.
+     */
+    public enum Type {
+        MD_ADDED,
+        MD_REMOVED,
+        MD_UPDATED
+    }
+
+    public MdEvent(Type type, MdId mdId) {
+        super(type, mdId);
+    }
+}