code: def _transaction_end(self):
          
          # Ask to return response bytes immediately.
          self._command.append('\x87')
          # Send the entire command to the MPSSE.
          self._ft232h._write(''.join(self._command))
          # Read response bytes and return them.
          return bytearray(self._ft232h._poll_read(self._expected))
docs: End I2C transaction and get response bytes, including ACKs.