def lexical_field_map(self) -> Dict[str, Field]:
        """Return a map from lexical field name to the field object.

        The field.lexical_field_name is not the same as the field.name. It is the name of the field that is used in the
        index schema with Marqo prefix."""
        return self._cache_or_get('lexical_field_map',
                                  lambda: {field.lexical_field_name: field for field in self.lexical_fields})
Return a map from lexical field name to the field object.

        The field.lexical_field_name is not the same as the field.name. It is the name of the field that is used in the
        index schema with Marqo prefix.
src/marqo/core/models/marqo_index.py