public function union($dals) {
		if(!is_array($dals))
			$dals = [$dals];
		$this->unions = array_merge($this->unions, $dals);

		return $this;
	}
public function union($dals) {
		if(!is_array($dals))
			$dals = [$dals];
		$this->unions = array_merge($this->unions, $dals);

		return $this;
	}
public function union ( $ dals ) { if ( ! is_array ( $ dals ) ) $ dals = [ $ dals ] ; $ this -> unions = array_merge ( $ this -> unions , $ dals ) ; return $ this ; }
Add UNIONs.
@param  array|static $dals
@return DAL
Add UNIONs .