title: How to get all functions of es6 class instance
body: <p>For example, I have some class with some methods:</p>
  
  <pre><code>class SomeClass() {
      someMethod1() {
      }
      someMethod2() {
      }
  }
  </code></pre>
  
  <p>Can I get all function names of this class instance?</p>
  
  <pre><code>Object.keys(new SomeClass()) 
  </code></pre>
  
  <p>gives me an empty array.</p>
  
  <p>I want to get array like <code>['someMethod1', 'someMethod2']</code>.</p>