public ContaCorrenteQuery(ContaBusiness business)
        {
            _business = business;

            Field <ListGraphType <ContaCorrenteType> >("saldo",
                                                       arguments: new QueryArguments(new QueryArgument[]
            {
                new QueryArgument <IntGraphType> {
                    Name = "conta"
                }
            }),
                                                       resolve: contexto =>
            {
                int numeroConta = contexto.GetArgument <int>("conta");
                return(_business.RetornaConta(numeroConta));
            }
                                                       );
        }