How to call private function from Controller to another Controller (Plugin)

I have a plugin Events,

I would like to add this part


   private function sendResetEmail($url, $user) {
    $email = new Email();
    $email->to($user->email, $user->full_name);
    $email->subject('Reset your password');
    $email->viewVars(['url' => $url, 'username' => $user->username]);
    if ($email->send()) {
        $this->Flash->success(__('Check your email for your reset password link'));
    } else {
        $this->Flash->error(__('Error sending email: ') . $email->smtpError);

To this part

EventController (INSIDE PLUGINS)

 $event = $this->Events->newEntity();
    if ($this->request->is('post')) {
        $event = $this->Events->patchEntity($event, $this->request->data);
        if ($this->Events->save($event)) {
            //function send_mail to user who crated Event
            $this->Flash->success(__('The event has been saved.'));
            return $this->redirect(['action' => 'index']);
        } else {
            $this->Flash->error(__('The event could not be saved. Please, try again.'));

Try to setup a listener

You could also see if anyone has done any videos on youtube on cakephp 3.x events.