code: func (s *SeesawEngine) VLANs(ctx *ipc.Context, reply *seesaw.VLANs) error {
  	s.trace("VLANs", ctx)
  	if ctx == nil {
  		return errors.New("context is nil")
  	}
  
  	if !ctx.IsTrusted() {
  		return errors.New("insufficient access")
  	}
  
  	if reply == nil {
  		return errors.New("VLANs is nil")
  	}
  	reply.VLANs = make([]*seesaw.VLAN, 0)
  	s.engine.vlanLock.RLock()
  	for _, vlan := range s.engine.vlans {
  		reply.VLANs = append(reply.VLANs, vlan)
  	}
  	s.engine.vlanLock.RUnlock()
  	return nil
  }
docs: // VLANs returns a list of VLANs configured for this cluster.