title: event.source undefined in simulated onFormSubmit event
body: <p>I have a google form that is linked to a google sheet.</p>
  
  <p>When I submit the actual form, onFormSubmit is triggered and my logs show " e.source  Spreadsheet"</p>
  
  <p>I was also using the simulated onFormSubmit code from this link (<a href="https://stackoverflow.com/questions/16089041/how-can-i-test-a-trigger-function-in-gas/16089067#16089067?newreg=8903a9e4e2834d15ad6a7e4a21688a4b">How can I test a trigger function in GAS?</a>)  to debug and everything <strong>was working fine</strong>. </p>
  
  <p><strong>Suddenly</strong> I am getting an error  "e.source  undefined" but e.values is working fine when I use the simulated onFormSubmit code. </p>
  
  <p>What could have caused this sudden error, particularly since it seemed to have been working fine before for exactly the same scenario?</p>
  
  <p>TIA</p>