class CreatePurchase:
    __metaclass__ = PoolMeta
    __name__ = 'purchase.request.create_purchase'

    @staticmethod
    def _get_tax_rule_pattern(request):
        pattern = super(CreatePurchase, CreatePurchase)._get_tax_rule_pattern(
            request)


-> AttributeError: 'super' object has no attribute '_get_tax_rule_pattern'