[has.tentative.html]
  [Calling StylePropertyMap.has with an unsupported property throws a TypeError]
    expected: FAIL

  [Calling StylePropertyMap.has with a custom property not in the property model returns false]
    expected: FAIL

  [Calling StylePropertyMap.has with a valid property returns true]
    expected: FAIL

  [Calling StylePropertyMap.has with a valid property in mixed case returns true]
    expected: FAIL

  [Calling StylePropertyMap.has with a valid custom property returns true]
    expected: FAIL

  [Calling StylePropertyMap.has with a valid list-valued property returns true]
    expected: FAIL

  [Calling StylePropertyMap.has with a valid shorthand property returns true]
    expected: FAIL