entry.go
func (e *Entry) SetMethodHandler(method string, h *Route) error {
	if e.GetHandler(method) != nil {
		return errors.New("Duplicate Route registration")
	}
	e.handlers[method] = h
	return nil
}
func (e *Entry) SetMethodHandler(method string, h *Route) error {
	if e.GetHandler(method) != nil {
		return errors.New("Duplicate Route registration")
	}
	e.handlers[method] = h
	return nil
}
// SetMethodHandler reigsters the given handler for the method.