CI_Session::set_flashdata PHP Method

    public function set_flashdata($data, $value = NULL)
    {
        $this->set_userdata($data, $value);
        $this->mark_as_flash(is_array($data) ? array_keys($data) : $data);
    }

 public function logout()
 {
     $response = $this->moneyzaurus->authenticateLogout();
     if ($response['code'] == 200) {
         if ($response['data']['success']) {
             $this->session->set_flashdata('success', 'Bye!');
         }
     }
     redirect('');
 }