How to get protected property of object in Magento (PHP)

2016-04-25T06:52:32+00:00 ALERT (1): Mage_Sales_Model_Order Object
(
    [_eventPrefix:protected] => sales_order
    [_eventObject:protected] => order
    [_addresses:protected] =>
    [_items:protected] =>
    [_payments:protected] =>
    [_statusHistory:protected] =>
    [_invoices:protected] =>
    [_tracks:protected] =>
    [_shipments:protected] =>
    [_creditmemos:protected] =>
    [_relatedObjects:protected] => Array
        (
        )

    [_orderCurrency:protected] =>
    [_baseCurrency:protected] =>
    [_actionFlag:protected] => Array
        (
        )

    [_canSendNewEmailFlag:protected] => 1
    [_historyEntityName:protected] => order
    [_resourceName:protected] => sales/order
    [_resource:protected] =>
    [_resourceCollectionName:protected] => sales/order_collection
    [_cacheTag:protected] =>
    [_dataSaveAllowed:protected] => 1
    [_isObjectNew:protected] =>
    [_data:protected] => Array
        (
            [entity_id] => 2052
            [state] => canceled

    ....   
    ....   
    ....
    ....
   
)

To get the _historyEntityName

          function accessProtected11($obj, $prop) {
            $reflection = new ReflectionClass($obj);
            if( $reflection->hasProperty($prop)){
            $property = $reflection->getProperty($prop);
            $property->setAccessible(true);
            return $property->getValue($obj);
        }
        return '';  
        }
       
        Mage::log(accessProtected($obj, _historyEntityName),true,'ordermail.log');