def max_packet_size(endpoint)
      endpoint = endpoint.bEndpointAddress if endpoint.respond_to? :bEndpointAddress
      res = Call.libusb_get_max_packet_size(@pDev, endpoint)
      LIBUSB.raise_error res, "in libusb_get_max_packet_size" unless res>=0
      res
    end
def max_packet_size(endpoint)
      endpoint = endpoint.bEndpointAddress if endpoint.respond_to? :bEndpointAddress
      res = Call.libusb_get_max_packet_size(@pDev, endpoint)
      LIBUSB.raise_error res, "in libusb_get_max_packet_size" unless res>=0
      res
    end
Convenience function to retrieve the wMaxPacketSize value for a
 particular endpoint in the active device configuration.

 @param [Endpoint, Fixnum] endpoint  (address of) the endpoint in question
 @return [Fixnum]  the wMaxPacketSize value