title: DeprecationWarning: Calling an asynchronous function without callback is deprecated. - how to find where the "function:" is?
body: <p>I recently updated my node to 7.2.1 and noticed that there is a warning coming:</p>
  
  <blockquote>
    <p>(node:4346) DeprecationWarning: Calling an asynchronous function without callback is deprecated.</p>
  </blockquote>
  
  <p>What is this <code>4346</code> for? I only have 2000 lines in the js file, so it can't be a line-number. Where can I find the code?</p>