WidgetPunchHole.php

<?php
class Packagename_Modulename_Model_Punchhole2 extends Enterprise_PageCache_Model_Container_Abstract
{
    protected function _getIdentifier()
    {
        return $this->_getCookieValue(Enterprise_PageCache_Model_Cookie::COOKIE_CUSTOMER, '');
    }

    /**
    * Get cache identifier
    *
    * @return string
    */
    protected function _getCacheId()
    {
        return 'HTML_CMSWIDGET_CACHED_ID' . md5($this->_placeholder->getAttribute('cache_id') . $this->_getIdentifier());
    }

    /**
    * Render block content
    *
    * @return string
    */
    protected function _renderBlock()
    {
        $block = $this->_placeholder->getAttribute('block');
        if($block == 'Mage_Cms_Block_Widget_Block'){
            $block = 'Mage_Cms_Block_Block';
        }
        $block = new $block;
        // Get the block_id attribute we originally set in our CMS block's
        // getCacheKeyInfo function.
        $block_id = $this->_placeholder->getAttribute('block_id');
        $block->setBlockId($block_id);
        $block->setLayout(Mage::app()->getLayout());
        return $block->toHtml();
    }

    protected function _saveCache($data, $id, $tags = array(), $lifetime = null)
    {
        return false;
    }
}