'immutable_datetime', 'arrival_date' => 'immutable_datetime', ]; public function user(): BelongsTo { return $this->belongsTo(User::class); } public function departureAirport(): BelongsTo { return $this->belongsTo(Airport::class, 'departure_airport_id'); } public function arrivalAirport(): BelongsTo { return $this->belongsTo(Airport::class, 'arrival_airport_id'); } public function airline(): BelongsTo { return $this->belongsTo(Airline::class); } public function aircraft(): BelongsTo { return $this->belongsTo(Aircraft::class); } public function seatType(): BelongsTo { return $this->belongsTo(SeatType::class); } public function flightClass(): BelongsTo { return $this->belongsTo(FlightClass::class); } public function flightReason(): BelongsTo { return $this->belongsTo(FlightReason::class); } }