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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 retrieve(customer, card_id):
 """ Retrieve a card from its id. :param customer: The customer id or object :type customer: string|Customer :param card_id: The card id :type card_id: string :return: The customer resource :rtype: resources.Card """

        if isinstance(customer, resources.Customer):
            customer = customer.id

        http_client = HttpClient()
        response, __ = http_client.get(routes.url(routes.CARD_RESOURCE, resource_id=card_id, customer_id=customer))
        return resources.Card(**response)