code: def invoice(self, **kwargs):
          
          url = urljoin(self._url, '/invoices')
  
          if kwargs:
              response = self.http_request(url, 'POST', Invoice(**kwargs), {'Content-Type':
                  'application/xml; charset=utf-8'})
          else:
              response = self.http_request(url, 'POST')
  
          if response.status != 201:
              self.raise_http_error(response)
  
          response_xml = response.read()
          logging.getLogger('recurly.http.response').debug(response_xml)
          elem = ElementTree.fromstring(response_xml)
  
          invoice_collection = InvoiceCollection.from_element(elem)
          return invoice_collection
docs: Create an invoice for any outstanding adjustments this account has.