  def test_should_sanitize_illegal_style_properties
    raw      = %(display:block; position:absolute; left:0; top:0; width:100%; height:100%; z-index:1; background-color:black; background-image:url(http://www.ragingplatypus.com/i/cam-full.jpg); background-x:center; background-y:center; background-repeat:repeat;)
    expected = %(display: block; width: 100%; height: 100%; background-color: black; background-x: center; background-y: center;)
    assert_equal expected, sanitize_css(raw)
  end
The software does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.