cmd/aefix/fix.go
func isIdent(n interface{}) *ast.Ident {
	id, _ := n.(*ast.Ident)
	return id
}
func isIdent(n interface{}) *ast.Ident {
	id, _ := n.(*ast.Ident)
	return id
}
// If n is an *ast.Ident, isIdent returns it; otherwise isIdent returns nil.