func (l *HandlerList) copy() HandlerList {
	var n HandlerList
	n.list = append([]NamedHandler{}, l.list...)
	return n
}
copy creates a copy of the handler list.
package request
type Handlers struct {
	Validate         HandlerList
	Build            HandlerList
	Sign             HandlerList
	Send             HandlerList
	ValidateResponse HandlerList
	Unmarshal        HandlerList
	UnmarshalMeta    HandlerList
	UnmarshalError   HandlerList
	Retry            HandlerList
	AfterRetry       HandlerList
}
func (h *Handlers) Copy() Handlers {
	return Handlers{
		Validate:         h.Validate.copy(),
		Build:            h.Build.copy(),
		Sign:             h.Sign.copy(),
		Send:             h.Send.copy(),
		ValidateResponse: h.ValidateResponse.copy(),
		Unmarshal:        h.Unmarshal.copy(),
		UnmarshalError:   h.UnmarshalError.copy(),
		UnmarshalMeta:    h.UnmarshalMeta.copy(),
		Retry:            h.Retry.copy(),
		AfterRetry:       h.AfterRetry.copy(),
	}
}
func (h *Handlers) Clear() {
	h.Validate.Clear()
	h.Build.Clear()
	h.Send.Clear()
	h.Sign.Clear()
	h.Unmarshal.Clear()
	h.UnmarshalMeta.Clear()
	h.UnmarshalError.Clear()
	h.ValidateResponse.Clear()
	h.Retry.Clear()
	h.AfterRetry.Clear()
}
type HandlerList struct {
	list []NamedHandler
}
type NamedHandler struct {
	Name string
	Fn   func(*Request)
}