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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _poll_trigger(self):
 """ Trigger activity for the caller by writting a NUL to the self-pipe. """

        try:
            os.write(self._poll_send, '\0'.encode('utf-8'))
        except Exception as e:
            log = self._getparam('log', self._discard)
            log.debug("Ignoring self-pipe write error -- %s", e)