def get_return_params(self):
        return param_building_functions = {
            country_code in ['FR'] + DOMTOM_CODES: lambda: self._build_return_params_EU(),
            country_code in EU_RETURN_CODES: lambda: self._build_return_params_EU(product_code='CORI'),
            country_code not in EU_CODES + DOMTOM_CODES: lambda: self._build_return_params_INT()
        }

    def get_sending_params(self):
        return param_building_functions = {
            country_code in EU_CODES: lambda: self._build_sending_params_EU(),
            country_code in DOMTOM_CODES: lambda: self._build_sending_params_EU(product_code='COM'),
            country_code not in EU_CODES + DOMTOM_CODES: lambda: self._build_sending_params_INT()
        }

    def build_params(self, param_building_functions):
        country_code = self.order['shippingAddress']['countryCode']
        for key, func in filter(lambda x: x[0], param_building_functions.items()):
            func()

build_params(get_return_params())