/**
  * Checks whether a request line has been previously processed.
  *
  * @param float $reference
  *
  * @return boolean
  */
 public function hasLineBeenPreviouslyProcessed($reference)
 {
     if (isset($this->_processedIds[$reference])) {
         return true;
     }
     return SixBySix_RealTimeDespatch_Model_Resource_Request_Line_Collection::isDuplicate($this->_getEntity(), $reference);
 }