Method decrease_usage

astra-sim/system/UsageTracker.cc:27–34

}

void UsageTracker::decrease_usage() {
  if (current_level > 0) {
    Usage u(current_level, last_tick, Sys::boostedTick());
    usage.push_back(u);
    current_level--;
    last_tick = Sys::boostedTick();
  }
}

void UsageTracker::set_usage(int level) {
  if (current_level != level) {