worker/simple.go
func (w *Simple) Register(name string, h Handler) error {
	w.moot.Lock()
	defer w.moot.Unlock()
	if _, ok := w.handlers[name]; ok {
		return fmt.Errorf("handler already mapped for name %s", name)
	}
	w.handlers[name] = h
	return nil
}
func (w *Simple) Register(name string, h Handler) error {
	w.moot.Lock()
	defer w.moot.Unlock()
	if _, ok := w.handlers[name]; ok {
		return fmt.Errorf("handler already mapped for name %s", name)
	}
	w.handlers[name] = h
	return nil
}
// Register Handler with the worker