original_string: public function addReference($ruleKey, $columns, $refTableClass, $refColumns,
                                   $onDelete = null, $onUpdate = null)
      {
          $reference = array(self::COLUMNS         => (array) $columns,
                             self::REF_TABLE_CLASS => $refTableClass,
                             self::REF_COLUMNS     => (array) $refColumns);
  
          if (!empty($onDelete)) {
              $reference[self::ON_DELETE] = $onDelete;
          }
  
          if (!empty($onUpdate)) {
              $reference[self::ON_UPDATE] = $onUpdate;
          }
  
          $this->_referenceMap[$ruleKey] = $reference;
  
          return $this;
      }
code: public function addReference($ruleKey, $columns, $refTableClass, $refColumns,
                                   $onDelete = null, $onUpdate = null)
      {
          $reference = array(self::COLUMNS         => (array) $columns,
                             self::REF_TABLE_CLASS => $refTableClass,
                             self::REF_COLUMNS     => (array) $refColumns);
  
          if (!empty($onDelete)) {
              $reference[self::ON_DELETE] = $onDelete;
          }
  
          if (!empty($onUpdate)) {
              $reference[self::ON_UPDATE] = $onUpdate;
          }
  
          $this->_referenceMap[$ruleKey] = $reference;
  
          return $this;
      }
code_tokens: public function addReference ( $ ruleKey , $ columns , $ refTableClass , $ refColumns , $ onDelete = null , $ onUpdate = null ) { $ reference = array ( self :: COLUMNS => ( array ) $ columns , self :: REF_TABLE_CLASS => $ refTableClass , self :: REF_COLUMNS => ( array ) $ refColumns ) ; if ( ! empty ( $ onDelete ) ) { $ reference [ self :: ON_DELETE ] = $ onDelete ; } if ( ! empty ( $ onUpdate ) ) { $ reference [ self :: ON_UPDATE ] = $ onUpdate ; } $ this -> _referenceMap [ $ ruleKey ] = $ reference ; return $ this ; }
docstring: Add a reference to the reference map
  
  @param string $ruleKey
  @param string|array $columns
  @param string $refTableClass
  @param string|array $refColumns
  @param string $onDelete
  @param string $onUpdate
  @return Zend_Db_Table_Abstract
docstring_tokens: Add a reference to the reference map