void ConnectionImpl::StreamImpl::submitMetadata(uint8_t flags) {
  ASSERT(stream_id_ > 0);
  const int result =
      nghttp2_submit_extension(parent_.session_, METADATA_FRAME_TYPE, flags, stream_id_, nullptr);
  ASSERT(result == 0);
}
void ConnectionImpl::StreamImpl::submitMetadata(uint8_t flags) {
  ASSERT(stream_id_ > 0);
  const int result =
      nghttp2_submit_extension(parent_.session_, METADATA_FRAME_TYPE, flags, stream_id_, nullptr);
  ASSERT(result == 0);
}