func (t *Target) hash() uint64 {
	h := fnv.New64a()
	h.Write([]byte(fmt.Sprintf("%016d", t.labels.Hash())))
	h.Write([]byte(t.URL().String()))

	return h.Sum64()
}
func (t *Target) hash() uint64 {
	h := fnv.New64a()
	h.Write([]byte(fmt.Sprintf("%016d", t.labels.Hash())))
	h.Write([]byte(t.URL().String()))

	return h.Sum64()
}
// hash returns an identifying hash for the target.