code: func (s *Store) Reset() {
  	s.mu.Lock()
  	s.metrics = make(map[string][]time.Duration)
  	s.mu.Unlock()
  	s.diffmu.Lock()
  	s.diffs = make(map[string]*diff)
  	s.diffmu.Unlock()
  }
docs: // Reset clears the metrics store.