{"ast_node_type":"other","tokens":[{"end":52,"kind":"keyword","start":0,"text":"//"}]}
                    // just using Fn* for iterators.
                    // FIXME(iter_macro): Someday we'll probably want iterator closures instead of
                    | hir::ClosureKind::CoroutineClosure(hir::CoroutineDesugaring::Gen) => {