code: function() {
          var string;
          if (OpenLayers.Format && OpenLayers.Format.CQL) {
              string = OpenLayers.Format.CQL.prototype.write(this);
          } else {
              string = Object.prototype.toString.call(this);
          }
          return string;
      }
docs: APIMethod: toString
  
  Returns:
  {String} Include <OpenLayers.Format.CQL> in your build to get a CQL
  representation of the filter returned. Otherwise "[Object object]"
  will be returned.