void verifyExpectedMetadata(Http::MetadataMap metadata_map, std::set<std::string> keys) {
  for (const auto& key : keys) {
    // keys are the same as their corresponding values.
    EXPECT_EQ(metadata_map.find(key)->second, key);
  }
  EXPECT_EQ(metadata_map.size(), keys.size());
}
void verifyExpectedMetadata(Http::MetadataMap metadata_map, std::set<std::string> keys) {
  for (const auto& key : keys) {
     
    EXPECT_EQ(metadata_map.find(key)->second, key);
  }
  EXPECT_EQ(metadata_map.size(), keys.size());
}