code: function decodeCssEscape(s) {
      var i = parseInt(s.substring(1), 16);
      // If parseInt didn't find a hex diigt, it returns NaN so return the
      // escaped character.
      // Otherwise, parseInt will stop at the first non-hex digit so there's no
      // need to worry about trailing whitespace.
      if (i > 0xffff) {
        // A supplemental codepoint.
        return i -= 0x10000,
          String.fromCharCode(
              0xd800 + (i >> 10),
              0xdc00 + (i & 0x3FF));
      } else if (i == i) {
        return String.fromCharCode(i);
      } else if (s[1] < ' ') {
        // "a backslash followed by a newline is ignored".
        return '';
      } else {
        return s[1];
      }
    }
docs: Decodes an escape sequence as specified in CSS3 section 4.1.
  http://www.w3.org/TR/css3-syntax/#characters
  @private