code: def open(self):
          
          handle = libusb1.libusb_device_handle_p()
          mayRaiseUSBError(libusb1.libusb_open(self.device_p, byref(handle)))
          result = USBDeviceHandle(self.__context, handle, self)
          self.__close_set.add(result)
          return result
docs: Open device.
          Returns an USBDeviceHandle instance.