public ContributorMutation(IContributorRepository repository) { FieldAsync <ContributorQueryType>( "addContributor", arguments: new QueryArguments(new QueryArgument <NonNullGraphType <ContributorCreateViewModel> > { Name = "contributor" }), resolve: async context => { var contributor = context.GetArgument <Contributor>("contributor"); return(await context.TryAsyncResolve(async _ => await repository.AddAsync(contributor))); } ); FieldAsync <ContributorQueryType>( "removeContributor", arguments: new QueryArguments(new QueryArgument <NonNullGraphType <StringGraphType> > { Name = "id" }), resolve: async context => { var id = context.GetArgument <string>("id"); return(await context.TryAsyncResolve( async _ => await repository.RemoveAsync(Guid.Parse(id)) )); } ); }