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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 _parent_queryset(self):
 """ Get queryset of parent view. Generated queryset is used to run queries in the current level view. """

        parent = self._resource.parent
        if hasattr(parent, 'view'):
            req = self.request.blank(self.request.path)
            req.registry = self.request.registry
            req.matchdict = {
                parent.id_name: self.request.matchdict.get(parent.id_name)}
            parent_view = parent.view(parent.view._factory, req)
            obj = parent_view.get_item(**req.matchdict)
            if isinstance(self, ItemSubresourceBaseView):
                return
            prop = self._resource.collection_name
            return getattr(obj, prop, None)