code: func (p *Profile) ScaleN(ratios []float64) error {
  	if len(p.SampleType) != len(ratios) {
  		return fmt.Errorf("mismatched scale ratios, got %d, want %d", len(ratios), len(p.SampleType))
  	}
  	allOnes := true
  	for _, r := range ratios {
  		if r != 1 {
  			allOnes = false
  			break
  		}
  	}
  	if allOnes {
  		return nil
  	}
  	for _, s := range p.Sample {
  		for i, v := range s.Value {
  			if ratios[i] != 1 {
  				s.Value[i] = int64(float64(v) * ratios[i])
  			}
  		}
  	}
  	return nil
  }
docs: // ScaleN multiplies each sample values in a sample by a different amount.