code: def is_connected(self):
          
          if self._is_open:
              err = hidapi.hid_read_timeout(self._device, ffi.NULL, 0, 0)
              if err == -1:
                  return False
              else:
                  return True
          else:
              en = Enumeration(vid=self.vendor_id, pid=self.product_id).find(path=self.path)
              if len(en) == 0:
                  return False
              else:
                  return True
docs: Checks if the USB device is still connected