code: def begin(self):
          
          # Assert CS pin low for a second for PN532 to be ready.
          self._gpio.set_low(self._cs)
          time.sleep(1.0)
          # Call GetFirmwareVersion to sync up with the PN532.  This might not be
          # required but is done in the Arduino library and kept for consistency.
          self.get_firmware_version()
          self._gpio.set_high(self._cs)
docs: Initialize communication with the PN532.  Must be called before any
          other calls are made against the PN532.