public PropertiesMutation(IPropertiesService service) { FieldAsync <StringGraphType>( "createOrUpdatePropertyNote", arguments: new QueryArguments( new QueryArgument <NonNullGraphType <CreateOrUpdatePropertyNoteInputType> > { Name = "propertyNote" }), resolve: async context => { var input = await context.GetValidatedArgumentAsync <PropertyNoteInput>("propertyNote"); await service.AddNoteToPropertyAsync(input.PropertyId, input.Note); return(input.Note); }); }