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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 postalCodeLookup(self, countryCode, postalCode):
 """ Looks up locations for this country and postal code. """

        params = {"country": countryCode, "postalcode": postalCode}
        d = self._call("postalCodeLookupJSON", params)
        d.addCallback(operator.itemgetter("postalcodes"))
        return d