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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 get_queryset(self):
 """ Retrieve the tag by his name and build a queryset of his published entries. """

        self.tag = get_tag(self.kwargs['tag'])
        if self.tag is None:
            raise Http404(_('No Tag found matching "%s".') %
                          self.kwargs['tag'])
        return TaggedItem.objects.get_by_model(
            Entry.published.all(), self.tag)