[clamp-length-serialize.html]
  [e.style['letter-spacing'\] = "clamp(1px, 2px, clamp(2px, 3px, 4px))" should set the property value]
    expected: FAIL

  [e.style['letter-spacing'\] = "clamp(1px, 2px, 3px)" should set the property value]
    expected: FAIL