[parser-fallsback-to-unknown-element.html]
  [HTML parser must create a fallback HTMLUnknownElement when a custom element constructor returns a Text node]
    expected: FAIL

  [HTML parser must create a fallback HTMLUnknownElement when a custom element constructor returns non-Element object]
    expected: FAIL

  [HTML parser must create a fallback HTMLUnknownElement when a custom element constructor does not call super()]
    expected: FAIL

  [HTML parser must create a fallback HTMLUnknownElement when a custom element constructor throws an exception]
    expected: FAIL