code: func (p *PromParser) Type() ([]byte, MetricType) {
  	return p.l.b[p.offsets[0]:p.offsets[1]], p.mtype
  }
docs: // Type returns the metric name and type in the current entry.
  // Must only be called after Next returned a type entry.
  // The returned byte slices become invalid after the next call to Next.