ONOS-5718 Dynamic Config APIs with RPC and Notification support

Change-Id: I670890efee83c86c7a3b242783c0a62879059849
diff --git a/apps/config/src/main/java/org/onosproject/config/RpcOutput.java b/apps/config/src/main/java/org/onosproject/config/RpcOutput.java
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index 0000000..3e7d4b3
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+++ b/apps/config/src/main/java/org/onosproject/config/RpcOutput.java
@@ -0,0 +1,80 @@
+/*
+ * Copyright 2016-present 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.config;
+
+import org.onosproject.config.model.DataNode;
+
+/**
+ * Abstraction for RPC output.
+ */
+public class RpcOutput {
+    public enum Status {
+        /**
+         * RPC execution was successful.
+         */
+        RPC_SUCCESS,
+        /**
+         * RPC execution failed.
+         */
+        RPC_FAILURE,
+        /**
+         * RPC execution don't have any output data.
+         */
+        RPC_NODATA,
+        /**
+         * Failed to receive a response from the receiver, within the broker specified timeout.
+         */
+        RPC_TIMEOUT,
+    }
+
+    /**
+     * Status of RPC execution.
+     */
+    Status status;
+    /**
+     * Output data from the RPC execution.
+     */
+    DataNode output;
+
+    /**
+     * Creates an instance of RpcOutput.
+     *
+     * @param status of RPC execution
+     * @param output of RPC execution
+     */
+    public RpcOutput(Status status, DataNode output) {
+        this.status = status;
+        this.output = output;
+    }
+
+    /**
+     * Returns RPC status.
+     *
+     * @return Status
+     */
+    public RpcOutput.Status status() {
+        return this.status;
+    }
+
+    /**
+     * Returns RPC output.
+     *
+     * @return DataNode
+     */
+    public DataNode output() {
+        return this.output;
+    }
+}
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