public function addPassenger(Passenger $passenger)
    {
        if ($this->passenger === null) {
            $this->passenger = [];
        }

        $this->passenger[] = $passenger;

        return $this;
    }
public function addPassenger(Passenger $passenger)
    {
        if ($this->passenger === null) {
            $this->passenger = [];
        }

        $this->passenger[] = $passenger;

        return $this;
    }
public function addPassenger ( Passenger $ passenger ) { if ( $ this -> passenger === null ) { $ this -> passenger = [ ] ; } $ this -> passenger [ ] = $ passenger ; return $ this ; }
@param Passenger $passenger

@return Flight
@param Passenger $passenger