<?php

/**
 * @package shop
 * @subpackage exceptions
 */
class ShopBuyableException extends Exception {
	
}

/**
 * @package shop
 * @subpackage exceptions
 */
class ShopBuyableException_NotEnoughStock extends ShopBuyableException {
	
}
<?php

/**
 * @package shop
 * @subpackage exceptions
 */
class ShopBuyableException extends Exception {
	
}

Remove reference of stock from the main module.
Remove reference of stock from the main module.
