public ActionResult <CreateRoomResultModel> CreateRoom(int roomId) { var room = RoomList.FindRoom(roomId); if (!(room is null)) { return(new CreateRoomResultModel() { ExistRoom = true }); } RoomList.CreateRoom(roomId); HttpContext.Session.SetInt32(KeyRoomId, roomId); Response.Cookies.Append(KeyRoomId, roomId.ToString()); return(new CreateRoomResultModel()); }