namespace System.Runtime.CompilerServices { public struct AsyncTaskMethodBuilder<TResult> { public Task<TResult> Task { get; } public void AwaitOnCompleted<TAwaiter, TStateMachine>(ref TAwaiter awaiter, ref TStateMachine stateMachine) where TAwaiter : INotifyCompletion where TStateMachine : IAsyncStateMachine; public void AwaitUnsafeOnCompleted<TAwaiter, TStateMachine>(ref TAwaiter awaiter, ref TStateMachine stateMachine) where TAwaiter : ICriticalNotifyCompletion where TStateMachine : IAsyncStateMachine; public static AsyncTaskMethodBuilder<TResult> Create(); public void SetException(Exception exception); public void SetResult(TResult result); public void SetStateMachine(IAsyncStateMachine stateMachine); public void Start<TStateMachine>(ref TStateMachine stateMachine) where TStateMachine : IAsyncStateMachine; } }