{"ast_node_type":"other","tokens":[{"end":77,"kind":"keyword","start":0,"text":"self.source_map.field_map_back.insert(expr,"}]}
                            self.source_map.field_map_back.insert(expr, src);
                            let src = self.expander.in_file(AstPtr::new(&field));
                            Some(RecordLitField { name, expr })