anchor.diff:  
       observer.observe(document.documentElement, attributes: true, subtree: true)
     else
  -    onTogglingClick (element) ->
  +    onTogglingTrigger (element) ->
         open = element.getAttribute("open")
         setTimeout ->
           unless element.getAttribute("open") is open
  
positive.code:   polyfillStyles()
    polyfillProperties()
    polyfillToggle()
  
  if support.element and not support.toggleEvent
    polyfillToggleEvent()
  
negative.code:     event.target.isContentEditable
    )
  
  keydownEventIsSignificant = (event) ->
    not (
      event.defaultPrevented or
      (event.keyCode != 32 and event.keyCode != 13) or
      event.altKey or
      event.ctrlKey or
      event.metaKey or
      event.shiftKey or
      event.target.isContentEditable
    )
  
  onTogglingTrigger = (callback) ->
    addEventListener "click", (event) ->
      if clickEventIsSignificant(event)
        if element = findClosestElementWithTagName(event.target, "SUMMARY")
          if element.parentElement?.tagName is "DETAILS"
            callback(element.parentElement)
    , false
  
    addEventListener "keydown", (event) ->
      if keydownEventIsSignificant(event)
        if element = findClosestElementWithTagName(event.target, "SUMMARY")
          if element.parentElement?.tagName is "DETAILS"
            callback(element.parentElement)
            # Prevent pagedown from space key
            event.preventDefault()
    , false
  
  findClosestElementWithTagName = do ->
  