refactor: clean up code

Author: NotSugden

src/client.js

@@ -262,6 +262,11 @@ class RPCClient extends EventEmitter {
   /**
    * Message handler
    * @param {Object} message message
+   * @param {?Object} message.args The arguments for the event, if any
+   * @param {string} message.cmd The command sent
+   * @param {string} message.evt The event
+   * @param {object} message.data The data for this message
+   * @param {?string} message.nonce The nonce
    * @private
    */
   _onRpcMessage({ args, cmd: command, data, evt: event, nonce }) {