Nighthawk currently defines its output as follows:

message Result {
  string name = 1;
  repeated Statistic statistics = 2;
  repeated Counter counters = 3;
}

message Output {
  google.protobuf.Timestamp timestamp = 1;
  nighthawk.client.CommandLineOptions options = 2;
  re

Statistics and counters have an id property. Consumers may become reliant on a specific id to be emitted.

A concrete example arose in the PR that adds an output transform for Fortio's format.
That relies on a) the aggregated global results to be around, and b) the a statistic with id benchmark_http_client.request_to_response.

Context: https://github.com/envoyproxy/nighthawk/pull/168/files/932814f6ee21ae4e2670fecfb42f80bbfd623afb#r341337505