for name, used := range functions {
		if !used {
			delete(f.Name, name)
		}
	}
}

// rewriteName returns the expression used to rewrite a reference.
// If addPosition is true, add position info in the ident name.
func (p *Package) rewriteName(f *File, r *Ref, addPosition bool) ast.Expr {
	getNewIdent := ast.NewIdent
	if addPosition {
		getNewIdent = func(newName string) *ast.Ident {