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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def getProductUIDs(self):
 """ return the uids of the products referenced by order items """

        uids = []
        for orderitem in self.objectValues('XupplyOrderItem'):
            product = orderitem.getProduct()
            if product is not None:
                uids.append(orderitem.getProduct().UID())
        return uids