private async Task SerializeTextToStreamAsync(Stream stream)
{
using var base64RequestStream = new Base64RequestStream(stream);
await _inner.CopyToAsync(base64RequestStream).ConfigureAwait(false);
// Any remaining content needs to be written when SerializeToStreamAsync finishes.
// We want to avoid unnecessary flush calls so a custom method is used to write
// ramining content rather than calling FlushAsync.
await base64RequestStream.WriteRemainderAsync(CancellationToken.None).ConfigureAwait(false);
}
