//adds a new airliner class to the airliner public void AddAirlinerClass(AirlinerClass airlinerClass) { if (airlinerClass != null) { if (Classes.Exists(c => c.Type == airlinerClass.Type)) { Classes[Classes.FindIndex(c => c.Type == airlinerClass.Type)] = airlinerClass; } else { Classes.Add(airlinerClass); if (airlinerClass.GetFacilities().Count == 0) { airlinerClass.CreateBasicFacilities(Airline); } } } }