title: Google Optimize - execute JS only if redirect did not happen
body: <p>I have a Google Optimize Redirect test running.
  I need to postpone the execution of some JavaScript on PageA (the non-redirected page) until I know that Google Optimize is NOT doing a redirect to PageB.
  Is there some event that is fired by Google Optimize telling the browser to redirect and/or not to redirect?
  Thanks</p>