code: def get_feature_report(self, report_id, length):
          
          self._check_device_status()
          bufp = ffi.new("unsigned char[]", length+1)
          buf = ffi.buffer(bufp, length+1)
          buf[0] = report_id
          rv = hidapi.hid_get_feature_report(self._device, bufp, length+1)
          if rv == -1:
              raise IOError("Failed to get feature report from HID device: {0}"
                            .format(self._get_last_error_string()))
          return buf[1:]
docs: Get a feature report from the device.
  
          :param report_id:   The Report ID of the report to be read
          :type report_id:    int
          :return:            The report data
          :rtype:             str/bytes