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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 load_queryset(self, query_data, request, *args, **kwargs):
 """ Fetches the queryset and runs any necessary filtering, both built-in rest_framework filters and custom filters passed into the querylist """

        queryset = query_data.get('queryset', [])

        if isinstance(queryset, QuerySet):
            # Ensure queryset is re-evaluated on each request.
            queryset = queryset.all()

        # run rest_framework filters
        queryset = self.filter_queryset(queryset)

        # run custom filters
        filter_fn = query_data.get('filter_fn', None)
        if filter_fn is not None:
            queryset = filter_fn(queryset, request, *args, **kwargs)

        page = self.paginate_queryset(queryset)
        self.is_paginated = page is not None

        return page if page is not None else queryset