code: def _read_data(self, count):
          
          # Build a read request frame.
          frame = bytearray(count)
          frame[0] = PN532_SPI_DATAREAD
          # Send the frame and return the response, ignoring the SPI header byte.
          self._gpio.set_low(self._cs)
          self._busy_wait_ms(2)
          response = self._spi.transfer(frame)
          self._gpio.set_high(self._cs)
          return response
docs: Read a specified count of bytes from the PN532.