def get_context_data(self, **kwargs):
        context = super(InterventionListView, self).get_context_data(**kwargs)
        facets = facet_sort_ignoreaccents(self.queryset.facet_counts(), 'item_author')
        # update multi-choice fields based on facets in the data
        self.form.set_choices_from_facets(facets.get('fields'))