code: def __create(self, short_description, period, **kwargs):
          
          params = {
              'short_description': short_description,
              'period': period
          }
          return self.make_call(self.__create, params, kwargs)
docs: Call documentation: `/preapproval/create
          <https://www.wepay.com/developer/reference/preapproval#create>`_, plus
          extra keyword parameters:
  
          :keyword str access_token: will be used instead of instance's
             ``access_token``, with ``batch_mode=True`` will set `authorization`
             param to it's value.
  
          :keyword bool batch_mode: turn on/off the batch_mode, see
             :class:`wepay.api.WePay`
  
          :keyword str batch_reference_id: `reference_id` param for batch call,
             see :class:`wepay.api.WePay`
  
          :keyword str api_version: WePay API version, see
             :class:`wepay.api.WePay`