code: public function getTokens()
      {
          $tokens = ['accessToken' => null, 'refreshToken' => null];
          if ($this->oauth2Middleware instanceof OAuthMiddleware) {
              $tokens['accessToken'] = $this->oauth2Middleware->getAccessToken();
              $tokens['refreshToken'] = $this->oauth2Middleware->getRefreshToken();
          }
          if ($this->cache instanceof Cache && empty($tokens['accessToken']) && $this->cache->contains('oauth2accesstoken')) {
              $tokens['accessToken'] = unserialize($this->cache->fetch('oauth2accesstoken'));
          }
          if ($this->cache instanceof Cache && empty($tokens['accessToken']) && $this->cache->contains('oauth2refreshtoken')) {
              $tokens['refreshToken'] = unserialize($this->cache->fetch('oauth2refreshtoken'));
          }
          if (empty($tokens['accessToken'])) {
              $response = $this->getClient()->get('/');      // Trigger call to get a token. Don't care about the result.
              $tokens['accessToken'] = $this->oauth2Middleware->getAccessToken();
              $tokens['refreshToken'] = $this->oauth2Middleware->getRefreshToken();
          }
  
          return $tokens;
      }
docs: Gets the token used for authentication.
  
  @return array ['accessToken' => AccessToken|null, 'refreshToken' => RefreshToken|null]