title: how to replace `bind(this)` in es6
body: <p>I read some codes:</p>
  
  <pre><code>class XXXX {
    init() {
      MyOBJ.on('EVENTNAME', this.myfunction.bind(this)); // Line3, MyOBJ extends EventEmitter
    }
  }
  </code></pre>
  
  <p>Just curious how to use arrow function to replace Line3? Thanks </p>