Managers    []*Manager
	Mux         []*mux.Router
	Hosts       []string
	cleanupOnce sync.Once
	cancel      context.CancelFunc
}

// SetupTestGrid creates a new grid for testing purposes.
// Select the number of hosts to create.
// Call (TestGrid).Cleanup() when done.
func SetupTestGrid(n int) (*TestGrid, error) {
	hosts, listeners, err := getHosts(n)
	if err != nil {
		return nil, err
	}
	dialer := &net.Dialer{