[Element-interface-attachShadow.html]
  type: testharness
  [Check the existence of Element.attachShadow]
    expected: FAIL

  [Element.attachShadow must create an instance of ShadowRoot]
    expected: FAIL

  [Element.attachShadow must throw a InvalidStateError if the context object already hosts a shadow tree]
    expected: FAIL

  [Element.attachShadow must throw a NotSupportedError for button, details, input, marquee, meter, progress, select, textarea, and keygen elements]
    expected: FAIL