<?php

class Mage_Catalog_Model_Product {}
class Varien_Object {}
class Zend_Uri_Http {}
class Enterprise_CatalogEvent_Model_Observer {}
class My_Module_Model_Order {}

$a = new Mage_Catalog_Model_Product();
$b = new Varien_Object();
$c = new Zend_Uri_Http();
$d = new Enterprise_CatalogEvent_Model_Observer;
$e = new My_Module_Model_Order;