virtualx-engine/modules/mono/glue/cs_files/Interfaces/IAwaiter.cs

using System.Runtime.CompilerServices;

namespace Godot
{
    public interface IAwaiter : INotifyCompletion
    {
        bool IsCompleted { get; }

        void GetResult();
    }

    public interface IAwaiter<out TResult> : INotifyCompletion
    {
        bool IsCompleted { get; }

        TResult GetResult();
    }
}