public void Handle(AssignExerciseToWorkoutCommand command)
{
var exercises = _exerciseSetRepository.GetExerciseSets(command.Exercises);
var workout = Workout.Create();
workout.Description = command.Description;
workout.Exercises = exercises;
workout.UserId = command.UserId;
_workoutRepository.AddWorkout(workout);
_exerciseSetRepository.AssignWorkout(command.Exercises, workout);
}