code: func (m *model) RemoteSequence(folder string) (int64, bool) {
  	m.fmut.RLock()
  	fs, ok := m.folderFiles[folder]
  	cfg := m.folderCfgs[folder]
  	m.fmut.RUnlock()
  
  	if !ok {
  		// The folder might not exist, since this can be called with a user
  		// specified folder name from the REST interface.
  		return 0, false
  	}
  
  	var ver int64
  	for _, device := range cfg.Devices {
  		ver += fs.Sequence(device.DeviceID)
  	}
  
  	return ver, true
  }
docs: // RemoteSequence returns the change version for the given folder, as
  // sent by remote peers. This is guaranteed to increment if the contents of
  // the remote or global folder has changed.