code: func (p *Params) Clone() *Params {
  	if p == nil {
  		return NewParams()
  	}
  	return &Params{
  		insCost:        p.insCost,
  		subCost:        p.subCost,
  		delCost:        p.delCost,
  		maxCost:        p.maxCost,
  		minScore:       p.minScore,
  		bonusPrefix:    p.bonusPrefix,
  		bonusScale:     p.bonusScale,
  		bonusThreshold: p.bonusThreshold,
  	}
  }
docs: // Clone returns a pointer to a copy of the receiver parameter set, or of a new
  // default parameter set if the receiver is nil.