original_string: protected function _convertConstraintColumns($references)
      {
          if (is_string($references)) {
              return $this->_driver->quoteIdentifier($references);
          }
  
          return implode(', ', array_map(
              [$this->_driver, 'quoteIdentifier'],
              $references
          ));
      }
code: protected function _convertConstraintColumns($references)
      {
          if (is_string($references)) {
              return $this->_driver->quoteIdentifier($references);
          }
  
          return implode(', ', array_map(
              [$this->_driver, 'quoteIdentifier'],
              $references
          ));
      }
code_tokens: protected function _convertConstraintColumns ( $ references ) { if ( is_string ( $ references ) ) { return $ this -> _driver -> quoteIdentifier ( $ references ) ; } return implode ( ', ' , array_map ( [ $ this -> _driver , 'quoteIdentifier' ] , $ references ) ) ; }
docstring: Convert foreign key constraints references to a valid
  stringified list
  
  @param string|array $references The referenced columns of a foreign key constraint statement
  @return string
docstring_tokens: Convert foreign key constraints references to a valid stringified list