async keyword generates a different public API

[SeanFeldman]

If understood correctly, async keyword is just a syntax sugar and shouldn't change public API.
Right now it does. Here's a repro:

public interface ITopology
{
    Task<bool> RunChecks();
}

public class A : ITopology 
{
    public Task<bool> RunChecks()
    {
        return Task.FromResult(true);
    }
}

public class B : ITopology
{
    public async Task<bool> RunChecks()
    {
        await Task.Delay(1); // mimicing some other call
        await Task.Delay(2); // mimicing some other call
        // logic to generate returned result based on invocations
        return true;
    }
}

Generate code is:

public class A : ITopology
{
        public System.Threading.Tasks.Task<bool> RunChecks() { }
}   

public class B : ITopology
{
        public async System.Threading.Tasks.Task<bool> RunChecks() { }
}

[danielmarbach]

@SeanFeldman The async keyword should not be part of the public API at all. I submitted a PR #26

The async keyword is an implementation detail since it is just syntactic sugar. From an API perspective the following APIs are equivalent:

• async void vs. void
• async Task vs Task
• async Task<T> vs Task<T>

From a behavior perspective you could argue that the runtime behavior from void to async void can change and therefore it could be a breaking change but from an API perspective both APIs are binary compatible. Since API approver's concern is only the public API the async keyword should be omitted. Thoughts?