server

var (
	// ErrNoListeners is returned when Server.Serve() is called before
	// Server.Listen()
	ErrNoListeners = errors.New("server: no listeners defined")

	// ErrMissingListener is returned by Server.Serve() when the number of
	// listeners created by Server.Listen() doesn't match the number of
	// listeners set in Config.Listeners.
	ErrMissingListener = errors.New("server: missing listener")

	// ErrAlreadyServing is returned by Server.Serve() when there are already
	// servers listening.  Before calling Server.Serve() again, Server.Close()
	// should be called to ensure all servers and listeners are closed.
	ErrAlreadyServing = errors.New("server: already serving")
)