code: def getMaxISOPacketSize(self, endpoint):
          
          result = libusb1.libusb_get_max_iso_packet_size(self.device_p, endpoint)
          mayRaiseUSBError(result)
          return result
docs: Get the maximum size for a single isochronous packet for given
          endpoint.
  
          Warning: this function will not always give you the expected result.
          See https://libusb.org/ticket/77 . You should instead consult the
          endpoint descriptor of current configuration and alternate setting.