code: function(func, args){
          var object;
          if (this.hasMoreRows()){
              object = func.call(this, args);
              this.nextRow();
          }
          else object = false;
          return object;
      }
docs: Fetch the values using a custom callback function.
  If there are rows to fetch, the custom function is called in scope of the rowset, so you can use <code>this</code> inside the custom function to refer to the rowset object.
  Then, the internal row pointer is increased so the next call will read the next row.
  The method returns whatever object or value is returned by the custom function, or false when there are no more rows to traverse.
  
  @method fetchCustom
  @param func {function} a custom function to extract and return the data from the current row of the xml result.
  @param args {object} an object that will be passed to the function. Useful to hold any data required in addition to the rowset itself (which can be referred to as this inside the function).
  @return {mixed|boolean}