code: function PropertyName(text, hack, line, col){
      
      SyntaxUnit.call(this, (hack||"") + text, line, col);
  
      /**
       * The type of IE hack applied ("*", "_", or null).
       * @type String
       * @property hack
       */
      this.hack = hack;
  
  }
docs: /*
  nth
  : S* [ ['-'|'+']? INTEGER? {N} [ S* ['-'|'+'] S* INTEGER ]? |
  ['-'|'+']? INTEGER | {O}{D}{D} | {E}{V}{E}{N} ] S*
  ;
   
  Represents a selector combinator (whitespace, +, >).
  @namespace parserlib.css
  @class PropertyName
  @extends parserlib.util.SyntaxUnit
  @constructor
  @param {String} text The text representation of the unit.
  @param {String} hack The type of IE hack applied ("*", "_", or null).
  @param {int} line The line of text on which the unit resides.
  @param {int} col The column of text on which the unit resides.