Ayuda controlador

tengo este controlador pero al llamar las funciones successresponse y errorresponse me sale error "No se pude llamar la funcion success_response de indefinida" Gracias ```php <?php

class SignupController extends BaseController{

    public function registerAction(){

        if ($this->request->isPost()){
            $user = new Users();

            $name = $this->request->getPost("name");
            $last_name = $this->request->getPost("last_name");
            $email = $this->request->getPost("email");
            $password = $this->request->getPost("password");

            $user->name = $name;
            $user->last_name = $last_name;
            $user->email = $email;
            $user->password = $password;


            if($user->save()){
                success_response($user);
            }
            else{
                $error = "Error not save user in db";
                error_response($error);
            }
        }
        else{
            $error = "Not request permited";
            error_response($error);
        }
    }

    protected function success_response($data){
        $success_array = array("success" => true,
                               "data" => $data);

        echo json_encode($success_array);
    }

    protected function error_response($error){
        $error_array = array("success" => false,
                             "error" => $error);

        echo json_encode($error_array);
    }
}

?>```

Como errorresponse y successresponse son m├ętodos del controlador debes usar $this para llamar esas funciones:

$this->success_response($user);
$this->error_response($error);

Muchas gracias :D