code: func (s *Reporter) Delete(ctx context.Context, key []byte) error {
  	start := s.Clock().Now()
  	err := s.Backend.Delete(ctx, key)
  	writeLatencies.WithLabelValues(s.Component).Observe(time.Since(start).Seconds())
  	writeRequests.WithLabelValues(s.Component).Inc()
  	if err != nil && !trace.IsNotFound(err) {
  		writeRequestsFailed.WithLabelValues(s.Component).Inc()
  	}
  	s.trackRequest(OpDelete, key, nil)
  	return err
  }
docs: // Delete deletes item by key