title: What findOne returns when there is no match?
body: <p>My <code>nodejs</code> app needs to check if <code>findOne</code> find any match.  </p>
  
  <pre><code>  let o = await Model.findOne({where : {name: 'myname'}});
    if (no match in o ) {
    //do something
    } else {
    //do something else
    };
  </code></pre>
  
  <p>But I did not find any document explaining what <code>findOne</code> returns when there is no match. I know it does not return <code>null</code> or <code>undefined</code>. The return is an object and how I know there is no match. </p>