code: func (s *memory) Update(c *source.ChangeSet) {
  	// don't process nil
  	if c == nil {
  		return
  	}
  
  	// hash the file
  	s.Lock()
  	// update changeset
  	s.ChangeSet = &source.ChangeSet{
  		Data:      c.Data,
  		Format:    c.Format,
  		Source:    "memory",
  		Timestamp: time.Now(),
  	}
  	s.ChangeSet.Checksum = s.ChangeSet.Sum()
  
  	// update watchers
  	for _, w := range s.Watchers {
  		select {
  		case w.Updates <- s.ChangeSet:
  		default:
  		}
  	}
  	s.Unlock()
  }
docs: // Update allows manual updates of the config data.