message: Fix documentation code bug
diff: @@ -17,7 +17,7 @@ import { Injectable } from '@graphql-modules/di';
  export class UserProvider {
  users = [
  {
  - _id: 0,
  + _id: '0',
  username: 'jhon',
  }
  ];
  @@ -51,7 +51,7 @@ import { GraphQLModule } from '@graphql-modules/core';
  import { UserProvider } from './user.provider';
  export default {
  Query: {
  - user: (root, { id }, { injector }) => injector.get(UserProvider).getUserById(id), UserProvider),
  + user: (root, { id }, { injector }) => injector.get(UserProvider).getUserById(id),
  },
  User: {
  id: user => user._id,
  