func (r *referrersResult) toSerial(res *serial.Result, fset *token.FileSet) {
	referrers := &serial.Referrers{
		Pos:  fset.Position(r.query.Pos()).String(),
		Desc: r.obj.String(),
	}
	if pos := r.obj.Pos(); pos != token.NoPos { // Package objects have no Pos()
		referrers.ObjPos = fset.Position(pos).String()
	}
	for _, ref := range r.refs {
		referrers.Refs = append(referrers.Refs, fset.Position(ref.NamePos).String())
	}
	res.Referrers = referrers
}