how to overload accessible methods

As we all know, __call() can overload non-accessible methods, eg. Class User { public function __call($name, $args) { //validate user.... $this->_validate(); $this->_{$name}($args); } private function _validate() { //.... } private function _update($args) { //.... } } $user = new User(); $user->update() // will call _validate before _update automatically BUT, if I want to make this update a public function, how can I call the validate without call it inside update function explicitly?