def _build_field_map(self, facets: FacetsParameters) -> Dict[str, Any]:
        """Build a mapping from field names to their facet parameters."""
        return {
            facet_field[0]: facet_field[1]
            for facet_field in facets.fields.items()
        }
Build a mapping from field names to their facet parameters.
src/marqo/core/semi_structured_vespa_index/semi_structured_vespa_index.py