code: func (a *AuthServer) createReverseTunnel(t services.TrustedCluster) error {
  	reverseTunnel := services.NewReverseTunnel(
  		t.GetName(),
  		[]string{t.GetReverseTunnelAddress()},
  	)
  	return trace.Wrap(a.UpsertReverseTunnel(reverseTunnel))
  }
docs: // createReverseTunnel will create a services.ReverseTunnel givenin the
  // services.TrustedCluster resource.