internal static async Task WaitForServerStreamExceptionAsync <THeader, TResult>(
IAsyncStreamReader <Message <TResult> > responseStream,
Metadata?responseHeaders,
Marshaller <THeader> marshaller,
CancellationToken token)
{
// here should throw the RpcException from server-side
// see ExceptionHandlingTestBase ThrowApplicationExceptionServerStreamingHeader and ThrowApplicationExceptionDuplexStreamingHeader
await responseStream.MoveNext(token).ConfigureAwait(false);
// this line should not be reached
// if the case, check for the headers content
CompatibilityTools.DeserializeMethodOutputHeader(marshaller, responseHeaders);
throw new InvalidOperationException("The server streaming ResponseHeadersAsync did not provide any headers, headers are available only after the streaming.");
}