title: How to access super class method inside of internal generator function?
body: <p>Look at this classes, Base and Derived, it's just simple classes that has "name" as property:</p>
  
  <pre><code>class Base {
      constructor(name) {
          this.name = name;
      }
      printName() {
          console.log("Base: " + this.name);
      }
  }
  
  class Derieved extends Base {
      constructor(name) {
          super(name);
      }
      // Override
      printName() {
          // IIFE.
          (function() {
              super.printName();  // Can't use super here
          })();
  
          console.log("Derived: " + this.name);
      }
  }
  
  var obj = new Derieved('John');
  obj.printName();
  </code></pre>
  
  <p>I want to invoke Base::printName from Derieved::printName. But some reason, I have to invoke inside of internal function of Derieved::printName.</p>
  
  <p>But run above code, it fails with:</p>
  
  <blockquote>
    <p>SyntaxError: 'super' keyword unexpected here</p>
  </blockquote>
  
  <p>If I saved the reference of parent's method to variable, looks like it can called but can't access any properties, it saids undefined.</p>
  
  <blockquote>
    <p>TypeError: Cannot read property 'name' of undefined</p>
  </blockquote>
  
  <p>I just wrote that internal function is just normal function, but actually it's generator function, so I can't use arrow function:</p>
  
  <pre><code>get(match: T, options: IQueryOptions|void): Promise&lt;Array&lt;Object&gt;|Error&gt; {
      const superGet = super.get;
  
      return new Promise((resolve, reject) =&gt; {
          co(function*() {
              try {
                      // I need to invoke parent's get method here!!
                  const accounts = yield superGet(match, options);
  
                  ... // do something with accounts
  
                  resolve(accounts);
              }
              catch(err) {
                  ...
              }
          });
      });
  }
  </code></pre>
  
  <p>Is there a way to to this? Why I can't save the reference of parent's method into variable?</p>