code: public function login($id, $userData)
      {
          $this->abortIfExpired($id, $userData);
  
          $u = new User();
          $u->setAuthenticated(true);
          $u->setAuthenticator($this->getName());
          $u->setId($id);
  
          if (isset($userData['groups'])) {
              $u->setGroups($userData['groups']);
          }
          if (isset($userData['displayName'])) {
              $u->setDisplayName($userData['displayName']);
          }
          if (isset($userData['attributes'])) {
              foreach ($userData['attributes'] as $key => $value) {
                  $u->setAttribute($key, $value);
              }
          }
          $this->picoAuth->setUser($u);
      }
docs: Logs the user in
  
  @param string $id User identifier
  @param array $userData User data array