protected abstract System.Threading.Tasks.ValueTask CloseAsyncCore(System.Net.Connections.ConnectionCloseMethod method, System.Threading.CancellationToken cancellationToken);
public System.Threading.Tasks.ValueTask CloseAsync(System.Net.Connections.ConnectionCloseMethod method = System.Net.Connections.ConnectionCloseMethod.GracefulShutdown, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken)) { throw null; }