public void AddPlanning(Guid movieId, Guid movieTheaterId, DateTime startTime, DateTime endTime)
{
var movieDb = GetById(movieId);
var movieTheaterDb = movieTheaterRepository.GetById(movieTheaterId);
var moviePlanningToAdd = MoviePlanning.Create(movieDb, movieTheaterDb, startTime, endTime);
movieRepository.AddPlanning(moviePlanningToAdd);
}