How to use the localstripe.resources.InvoiceItem function in localstripe

def __init__(self, item):
        try:
            assert isinstance(item, (InvoiceItem, SubscriptionItem))
        except AssertionError:
            raise UserError(400, 'Bad request')

        # All exceptions must be raised before this point.
        super().__init__()

        self.type = \
            'invoiceitem' if isinstance(item, InvoiceItem) else 'subscription'

        if self.type == 'subscription':
            self.subscription_item = item.id
            self.subscription = item._subscription
            self.plan = item.plan
            self.proration = False
            self.currency = item.plan.currency
            self.description = item.plan.name
            self.amount = item._calculate_amount()
            self.period = item._current_period()
        elif self.type == 'invoiceitem':
            self.invoice_item = item.id
            self.subscription = item.subscription
            self.plan = item.plan
            self.proration = item.proration
            self.currency = item.currency

'paid_at': None,
            'voided_at': None,
        }

        self.period_start = None
        self.period_end = None
        if subscription is not None:
            self.period_start = subscription_obj.current_period_start
            self.period_end = subscription_obj.current_period_end

        self.lines = List('/v1/invoices/' + self.id + '/lines')
        for item in items:
            item.invoice = self.id
            self.lines._list.append(InvoiceLineItem(item))

        pending_items = [ii for ii in InvoiceItem._api_list_all(
            None, customer=self.customer, limit=99)._list
            if ii.invoice is None]
        for ii in pending_items:
            if not simulation:
                ii.invoice = self.id
            self.lines._list.append(InvoiceLineItem(ii))

        if len(self.lines._list):
            self.currency = self.lines._list[0].currency
        else:
            self.currency = 'eur'  # arbitrary default

        self._draft = True
        self._voided = False

        if not simulation and not upcoming:

def _api_list_all(cls, url, customer=None, limit=None):
        try:
            if customer is not None:
                assert type(customer) is str and customer.startswith('cus_')
        except AssertionError:
            raise UserError(400, 'Bad request')

        li = super(InvoiceItem, cls)._api_list_all(url, limit=limit)
        li._list = [ii for ii in li._list if ii.invoice is None]
        if customer is not None:
            Customer._api_retrieve(customer)  # to return 404 if not existant
            li._list = [ii for ii in li._list if ii.customer == customer]
        li._list.sort(key=lambda i: i.date, reverse=True)
        return li

plan=items[0]['plan'],
                                        quantity=items[0]['quantity'],
                                        tax_rates=items[0]['tax_rates'])
                self.items._list.append(item)

                # Create unused time pending item.
                # Get previous invoice for this subscription and customer, and
                # deduce what is already paid:
                # TODO: Better not to use limit, but take date into account
                previous = Invoice._api_list_all(None, customer=self.customer,
                                                 subscription=self.id,
                                                 limit=99)
                for previous_invoice in previous._list:
                    previous_tax_rates = [tr.id for tr in (
                        previous_invoice.lines._list[0].tax_rates or [])]
                    InvoiceItem(amount=- previous_invoice.subtotal,
                                currency=previous_invoice.currency,
                                proration=True,
                                description='Unused time',
                                subscription=self.id,
                                plan=old_plan.id,
                                tax_rates=previous_tax_rates,
                                customer=self.customer)

            elif self.items._list[0].tax_rates != items[0]['tax_rates']:
                self.items = List('/v1/subscription_items?subscription=' +
                                  self.id)
                item = SubscriptionItem(subscription=self.id,
                                        plan=items[0]['plan'],
                                        quantity=items[0]['quantity'],
                                        tax_rates=items[0]['tax_rates'])
                self.items._list.append(item)

else:  # if simulation
            if subscription is not None:
                # Get previous invoice for this subscription and customer, and
                # deduce what is already paid:
                # TODO: Better not to use limit, but take date into account
                previous = cls._api_list_all(None, customer=customer,
                                             subscription=subscription,
                                             limit=99)
                for previous_invoice in previous._list:
                    old_plan = previous_invoice.lines._list[0].plan
                    old_tax_rates = [
                        tr.id
                        for tr in previous_invoice.lines._list[0].tax_rates]
                    invoice_items.append(
                        InvoiceItem(amount=- previous_invoice.subtotal,
                                    currency=previous_invoice.currency,
                                    proration=True,
                                    description='Unused time',
                                    subscription=subscription,
                                    plan=old_plan.id,
                                    tax_rates=old_tax_rates,
                                    customer=customer,
                                    period_start=previous_invoice.period_start,
                                    period_end=previous_invoice.period_end))

            invoice = cls(customer=customer,
                          items=invoice_items,
                          tax_percent=tax_percent,
                          default_tax_rates=default_tax_rates,
                          date=date,
                          description=description,