import { UsersService , MockUsersService } from './data-services' ; import { MOCK_USERS } from './mock-data' ; export class AppDataServices { public usersService : UsersService ; constructor ( useMock = true ) { if ( useMock ) { this . initMockDataServices ( ) ; } } private initMockDataServices ( ) { this . usersService = new MockUsersService ( MOCK_USERS ) ; } }