in spectator/stateless_meters.h [77:86]
void send(double value) {
if (value_prefix_.empty()) {
value_prefix_ = detail::create_prefix(*id_, Type());
}
auto msg = absl::StrFormat("%s%f", value_prefix_, value);
// remove trailing zeros and decimal points
msg.erase(msg.find_last_not_of('0') + 1, std::string::npos);
msg.erase(msg.find_last_not_of('.') + 1, std::string::npos);
publisher_->send(msg);
}