init.go
func Publish(channels []string, msg interface{}) error {
	if hubInstance == nil {
		return errorNohub
	}
	log.Debug("publish to %v", channels)
	hubInstance.Publish(channels, msg)
	return nil
}
func Publish(channels []string, msg interface{}) error {
	if hubInstance == nil {
		return errorNohub
	}
	log.Debug("publish to %v", channels)
	hubInstance.Publish(channels, msg)
	return nil
}
// Publish message to given channels.