code: public function setFPCDebug($status)
      {
          if (!Mage::helper('sheep_debug')->isMagentoEE()) {
              throw new Exception ('Cannot enable FPC debug for this Magento version.');
          }
  
          $this->getConfig()->saveConfig('system/page_cache/debug', (int)$status);
      }
docs: Enable/disables Full Page Cache debug
  
  @param int $status
  @throws Exception