<PackageReference Include="Microsoft.Bcl.AsyncInterfaces" Version="10.0.5" />

System.Runtime.CompilerServices.ConfiguredCancelableAsyncEnumerable<T>

Provides an awaitable async enumerable that enables cancelable iteration and configured awaits.
namespace System.Runtime.CompilerServices { public readonly struct ConfiguredCancelableAsyncEnumerable<[System.Runtime.CompilerServices.Nullable(2)] T> { public readonly struct Enumerator { public T Current { get; } public ConfiguredValueTaskAwaitable<bool> MoveNextAsync(); public ConfiguredValueTaskAwaitable DisposeAsync(); } public ConfiguredCancelableAsyncEnumerable<T> ConfigureAwait(bool continueOnCapturedContext); public ConfiguredCancelableAsyncEnumerable<T> WithCancellation(CancellationToken cancellationToken); public Enumerator GetAsyncEnumerator(); } }