code: func FuzzParseMetric(in []byte) int {
  	p := textparse.New(in)
  	for p.Next() {
  	}
  
  	if p.Err() == nil {
  		return fuzzInteresting
  	}
  
  	return fuzzMeh
  }
docs: // Fuzz the metric parser.
  //
  // Note that his is not the parser for the text-based exposition-format; that
  // lives in github.com/prometheus/client_golang/text.