/**
	 * Creates a new Zend_Service_WindowsAzure_Credentials_SharedAccessSignature instance
	 *
	 * @param string $accountName Account name for Windows Azure
	 * @param string $accountKey Account key for Windows Azure
	 * @param boolean $usePathStyleUri Use path-style URI's
	 * @param array $permissionSet Permission set
	 */
	public function __construct(
		$accountName = Zend_Service_WindowsAzure_Credentials_AbstractCredentials::DEVSTORE_ACCOUNT,
		$accountKey  = Zend_Service_WindowsAzure_Credentials_AbstractCredentials::DEVSTORE_KEY,
		$usePathStyleUri = false, $permissionSet = array()
	) {
	    parent::__construct($accountName, $accountKey, $usePathStyleUri);
	    $this->_permissionSet = $permissionSet;
	}