void Filter::UpstreamCallbacks::onBytesSent() {
  if (drainer_ == nullptr) {
    parent_->resetIdleTimer();
  } else {
    drainer_->onBytesSent();
  }
}
void Filter::UpstreamCallbacks::onBytesSent() {
  if (drainer_ == nullptr) {
    parent_->resetIdleTimer();
  } else {
    drainer_->onBytesSent();
  }
}