async interface c#

AsyncInterface.cs

interface IOperator
{
    Task Execute();
}

class FileWriter : IOperator  // async implementation
{
    public async Task Execute()
    {
        await File.WriteAllTextAsync("myfile1.txt", "hello");
        await File.WriteAllTextAsync("myfile2.txt", "bye");
    }
}

class DoNothing : IOperator // sync implementation
{
    public Task Execute()
    {
        return Task.CompletedTask;
    }
}