protected function _convertConstraintColumns($references)
    {
        if (is_string($references)) {
            return $this->_driver->quoteIdentifier($references);
        }

        return implode(', ', array_map(
            [$this->_driver, 'quoteIdentifier'],
            $references
        ));
    }
protected function _convertConstraintColumns($references)
    {
        if (is_string($references)) {
            return $this->_driver->quoteIdentifier($references);
        }

        return implode(', ', array_map(
            [$this->_driver, 'quoteIdentifier'],
            $references
        ));
    }
protected function _convertConstraintColumns ( $ references ) { if ( is_string ( $ references ) ) { return $ this -> _driver -> quoteIdentifier ( $ references ) ; } return implode ( ', ' , array_map ( [ $ this -> _driver , 'quoteIdentifier' ] , $ references ) ) ; }
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
Convert foreign key constraints references to a valid stringified list