using System;

using System.Threading.Tasks;

public class Program

{

    public static async Task Main()

    {

        var subject = new Subject(new FakeRepository());

        await subject.DoSomethingAsync();

    }

}

​

public class Subject

{

    private readonly IRepository _repository;

    public Subject(IRepository repository)

    {

        _repository = repository;

    }

    public async Task DoSomethingAsync()

    {

        /*await*/ _repository.InsertAsync(); // BUG, I forget to await this Task

        await _repository.GetAsync();

    }

}

​

public interface IRepository

{

    Task InsertAsync();

    Task GetAsync();

}

​

public class FakeRepository : IRepository

{

    public async Task InsertAsync()

    {

        // await Task.CompletedTask;

        await Task.Delay(10);

        Console.WriteLine("1. insert");

    }

    public async Task GetAsync()

    {

        // await Task.CompletedTask;

        await Task.Delay(10);

        Console.WriteLine("2. get");

    }

}