code: func (m *AgentPool) FetchAndSyncAgents() error {
  	tunnels, err := m.cfg.AccessPoint.GetReverseTunnels()
  	if err != nil {
  		return trace.Wrap(err)
  	}
  	if err := m.syncAgents(tunnels); err != nil {
  		return trace.Wrap(err)
  	}
  	return nil
  }
docs: // FetchAndSyncAgents executes one time fetch and sync request
  // (used in tests instead of polling)