Closes the device.

def close(self):
        """
        Closes the device.
        """
        try:
            # TODO: Find a way to speed up this shutdown.
            if self.ssl:
                self._device.shutdown()

            else:
                # Make sure that it closes immediately.
                self._device.shutdown(socket.SHUT_RDWR)

        except Exception:
            pass

        Device.close(self)