private async Task <IEnumerable <Mission> > GetMissionFunc(IResolveFieldContext <object> context) { var missionId = context.GetArgument <string>("missionId"); if (missionId != null) { var mission = await _missionEngine.GetMission(missionId); return(new List <Mission> { mission }); } var seriesId = context.GetArgument <string>("seriesId"); if (seriesId != null) { return(await _missionEngine.GetMissionsBySeriesId(seriesId)); } return(await _missionEngine.GetAll()); }