title: Error: call super outside of class constructor
body: <p>I try to call parent method but I get error: </p>
  
  <blockquote>
    <p>Error: call super outside of class constructor</p>
  </blockquote>
  
  <p>My example : </p>
  
  <pre><code>class xo{
      cool(x){
          console.log(`parent init${x}`)
      }
  }
  class boo extends xo{
      cool(val){
          super(val);
          console.log(`child init${x}`)
      }
  }
  
  x = new boo;
  </code></pre>