docs: def _get_adv_trans_stats(self, cmd, return_tdo=False):
          """Utility function to fetch the transfer statistics for the last
          advanced transfer. Checking the stats appears to sync the
          controller. For details on the advanced transfer please refer
          to the documentation at
          http://diamondman.github.io/Adapt/cable_digilent_adept.html#bulk-requests
  
          """
          t = time()
          code, res = self.bulkCommand(b'\x03\x02%c\x00'%(0x80|cmd), 10)
          if self._scanchain and self._scanchain._print_statistics:
              print("GET STATS TIME", time()-t)#pragma: no cover
          if len(res) == 4:
              count = struct.unpack('<I', res)[0]
              return count
          elif len(res) == 8:
              written, read =  struct.unpack('<II', res)
              return written, read
          return res