/**
  * Get all possible user roles.
  *
  * @return array
  */
 protected function getUserRoles()
 {
     if (!is_null($this->userRoles)) {
         return $this->userRoles;
     } elseif (!$this->auth->guest()) {
         return $this->auth->roles();
     }
     return $this->roles->has('guest') ? ['guest'] : [];
 }