private Task PopulateData(IUserManagementService service) { Console.WriteLine("Quantity:"); var quantityString = Console.ReadLine(); if (!int.TryParse(quantityString, out int quantity)) { return(Task.CompletedTask); } var rand = new Random(); Parallel.ForEach( source: Enumerable.Range(0, quantity), parallelOptions: new ParallelOptions { MaxDegreeOfParallelism = 10 }, body: async index => { var user = await service.CreateUser("A", "1", 18); await service.ChangeUserFirstName(user.Id, "B"); await service.ChangeUserFirstName(user.Id, "User"); await service.ChangeUserLastName(user.Id, "2"); await service.ChangeUserLastName(user.Id, index.ToString()); await service.ChangeUserAge(user.Id, 20); await service.ChangeUserAge(user.Id, rand.Next(20, 50)); Console.WriteLine($"{index} user was populated."); } ); return(Task.CompletedTask); }