code: func (r *ReadGroup) Clone() *ReadGroup {
  	if r == nil {
  		return nil
  	}
  	cr := *r
  	if len(cr.otherTags) != 0 {
  		cr.otherTags = make([]tagPair, len(cr.otherTags))
  	}
  	copy(cr.otherTags, r.otherTags)
  	cr.id = -1
  	cr.owner = nil
  	return &cr
  }
docs: // Clone returns a deep copy of the ReadGroup.