title: How to access koa context in another generator function?
body: <p>In Koa I can accesss a Koa Context in the first generator function via <code>this</code>:</p>
  
  <pre><code>app.use(function *(){
      this; // is the Context
  }
  </code></pre>
  
  <p>But if I yield to another generator function I can't access the context via <code>this</code> anymore.</p>
  
  <pre><code>app.use(function *(){
      yield myGenerator();
  }
  
  function* myGenerator() {
      this.request; // is undefined
  }
  </code></pre>
  
  <p>I've been able to simply pass the context to the second generator function, but was wondering whether there's a cleaner way to access the context.</p>
  
  <p>Any ideas?</p>