title: Call one function after another function having a async function in itself
body: <p>How to call one function <code>a()</code> after another function <code>b()</code> when <code>b()</code> contains a async function <code>c()</code>?</p>
  
  <pre><code>A() {
  
  }
  
  B() {
  
      //do sometihng
      c(); //async function 
      //do something
  
  }
  </code></pre>
  
  <p>I want to call <code>A()</code> if <code>B()</code> including <code>c()</code> is done executing. But I can not modify function B(). </p>