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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 update_team(self, slug):
 """ Trigger update and cache invalidation for the team identified by the given `slug`, if any. Returns `True` if the update was successful, `False` otherwise. :param slug: GitHub 'slug' name for the team to be updated. """

        if self._org:
            if not self._org.has_team(slug):
                return self._org.update()
            return self._org.update_team(slug)
        # self._org is created during Trac startup, so there should never
        # be a case where we try to update an org before it's created; this
        # is a sanity check only.
        return False