header.go
func (h *ResponseHeader) PeekCookie(key string) []byte {
	return peekArgStr(h.cookies, key)
}
func (h *ResponseHeader) PeekCookie(key string) []byte {
	return peekArgStr(h.cookies, key)
}
func ( h * ResponseHeader ) PeekCookie ( key string ) [ ] byte { return peekArgStr ( h . cookies , key ) }
// PeekCookie is able to returns cookie by a given key from response.
PeekCookie is able to returns cookie by a given key from response .