{"ast_node_type":"other","tokens":[{"end":84,"kind":"keyword","start":0,"text":"struct_def.fields().iter().enumerate().map(|(i,"}]}
                    struct_def.fields().iter().enumerate().map(|(i, struct_field)| {
                let pieces_iter =
                        let sp = struct_field.span.with_ctxt(self.span.ctxt());