public function map($map = null) {
		if ($map !== null) {
			$this->_map = $map;
			return $this;
		}
		return $this->_map;
	}
public function map($map = null) {
		if ($map !== null) {
			$this->_map = $map;
			return $this;
		}
		return $this->_map;
	}
public function map ( $ map = null ) { if ( $ map !== null ) { $ this -> _map = $ map ; return $ this ; } return $ this -> _map ; }
Generates a schema map of the query's result set, where the keys are aliases, and the values
are arrays of field names.

@param array $map
@return array
Generates a schema map of the query s result set where the keys are aliases and the values are arrays of field names .