anchor.diff:   */
   function displayFeedbackForm(video, recordID) {
     const feedbackForm = createFeedbackForm(video, recordID)
  -  const _onloadstart = video.onloadstart
  -  video.onloadstart = () => { removeElement(feedbackForm); _onloadstart() }
  +  addVideoEndAction(video, () => { removeElement(feedbackForm) })
     displayCalloutForForm(video)
     return feedbackForm
   }
  
positive.code:   const callout_display_length = Math.max(videoDurationInMS * 0.5, 1000)
    const defaultRemoveTimeout = setTimeout(removeElement, callout_display_length, callout)
  
    addClickEvent(callout, () => {
      clearTimeout(defaultRemoveTimeout)
      const feedbackForm = document.getElementById('pa-popout')
  
negative.code:     element.parentElement.removeChild(element)
    } catch(e) {
    }
  }
  
  function addVideoEndAction(video, action) {
    if (!video || !action) return
    const _onloadstart = video.onloadstart
    video.onloadstart = () => { action(); _onloadstart() }
  }
  
  function endVideo(video) {
  