public MyHotelMutation(MyHotelRepository myHotelRepository, INotifier notifier, IMapper mapper) { Name = "CreateGuestMutation"; Field <GuestType>( "createGuest", arguments: new QueryArguments( new QueryArgument <NonNullGraphType <GuestInputType> > { Name = "guest" } ), resolve: context => { var guestModel = context.GetArgument <GuestModel>("guest"); var guest = mapper.Map <Guest>(guestModel); var newGuest = myHotelRepository.AddGuest(guest); var newGuestModel = mapper.Map <GuestModel>(newGuest); notifier.AddGuest(newGuestModel); return(newGuestModel); }); }