let xGraphAdapter = require('xgraph-adapter'); class A extends xGraphAdapter { constructor(com) { super('192.168.2.209', 28000); this.ping(); } Pong(com, fun) { console.log('Pong!!'); this.ping(); } ping() { console.log('sending ping'); this.send('Ping', {}, (err, cmd) => { console.log('ping callback', err, cmd); }); } } new A();