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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 _mark_started(self):
 """ Set the state information for a task once it has completely started. In particular, the time limit is applied as of this time (ie after and start delay has been taking. """

        log = self._params.get('log', self._discard)

        now = time.time()
        self._started = now

        limit = self._config_running.get('time_limit')
        try:
            limit = float(_fmt_context(self._get(limit, default='0'), self._context))
            if limit > 0:
                log.debug("Applying task '%s' time limit of %s", self._name, deltafmt(limit))
                self._limit = now + limit
        except Exception as e:
            log.warn("Task '%s' time_limit value '%s' invalid -- %s",
                self._name, limit, e, exc_info=log.isEnabledFor(logging.DEBUG))