/**
  * Performs retrieving of file helper instance
  *
  * @param Mage_Selenium_TestCase $testCase Current test case as object (by default = NULL)
  * @param Mage_Selenium_Helper_Application $applicationHelper Current tested application as object (by default = NULL)
  *
  * @return Mage_Selenium_Helper_Page
  */
 public function getPageHelper($testCase = null, $applicationHelper = null)
 {
     if (is_null($this->_pageHelper)) {
         $this->_pageHelper = new Mage_Selenium_Helper_Page($this);
     }
     if (!is_null($testCase)) {
         $this->_pageHelper->setTestCase($testCase);
     }
     if (!is_null($applicationHelper)) {
         $this->_pageHelper->setApplicationHelper($applicationHelper);
     }
     return $this->_pageHelper;
 }