code: func (s *Sublist) removeFromCache(subject string) {
  	for k := range s.cache {
  		if !matchLiteral(k, subject) {
  			continue
  		}
  		// Since someone else may be referencing, can't modify the list
  		// safely, just let it re-populate.
  		delete(s.cache, k)
  	}
  }
docs: // removeFromCache will remove any active cache entries on that subject.
  // Assumes write lock is held.