code: public function clear($cacheContent = false): bool
      {
          $keys = [];
          foreach ($this->fetchResources($cacheContent) as $resource) {
              /** @var SystemPropertiesInterface $sys */
              $sys = $resource->getSystemProperties();
  
              $options = $sys instanceof LocalizedResourceSystemProperties
                  ? ['locale' => $sys->getLocale()]
                  : [];
              $keys[] = $this->resourcePool->generateKey($sys->getType(), $sys->getId(), $options);
          }
  
          return $this->cacheItemPool->deleteItems($keys);
      }
docs: @param bool $cacheContent
  
  @return bool