code: func (s *Set) List() []Dependency {
  	s.RLock()
  	defer s.RUnlock()
  	r := make([]Dependency, len(s.list))
  	for i, k := range s.list {
  		r[i] = s.set[k]
  	}
  	return r
  }
docs: // List returns the insertion-ordered list of dependencies.