code: def getFeatureReport(self, report_num=0, length=63):
          
          length += 1
          buf = bytearray(length)
          buf[0] = report_num
          self._ioctl(
              _HIDIOCGFEATURE(length),
              (ctypes.c_char * length).from_buffer(buf),
              True,
          )
          return buf
docs: Receive a feature report.
          Blocks, unless you configured provided file (descriptor) to be
          non-blocking.