func (t *Target) DiscoveredLabels() labels.Labels {
	t.mtx.Lock()
	defer t.mtx.Unlock()
	lset := make(labels.Labels, len(t.discoveredLabels))
	copy(lset, t.discoveredLabels)
	return lset
}
func (t *Target) DiscoveredLabels() labels.Labels {
	t.mtx.Lock()
	defer t.mtx.Unlock()
	lset := make(labels.Labels, len(t.discoveredLabels))
	copy(lset, t.discoveredLabels)
	return lset
}
// DiscoveredLabels returns a copy of the target's labels before any processing.