Address comments

Author: minggangw

lib/node.js

@@ -44,7 +44,6 @@ const Entity = require('./entity.js');
 const { SubscriptionEventCallbacks } = require('../lib/event_handler.js');
 const { PublisherEventCallbacks } = require('../lib/event_handler.js');
 const { validateFullTopicName } = require('./validator.js');
-const node = require('debug/src/node.js');
 
 // Parameter event publisher constants
 const PARAMETER_EVENT_MSG_TYPE = 'rcl_interfaces/msg/ParameterEvent';