uint32_t Filter::numRequestsAwaitingHeaders() {
  return std::count_if(upstream_requests_.begin(), upstream_requests_.end(),
                       [](const auto& req) -> bool { return req->awaitingHeaders(); });
}
uint32_t Filter::numRequestsAwaitingHeaders() {
  return std::count_if(upstream_requests_.begin(), upstream_requests_.end(),
                       [](const auto& req) -> bool { return req->awaitingHeaders(); });
}