syntax_data: {"ast_node_type":"other","tokens":[{"end":47,"kind":"keyword","start":0,"text":"std::iter::repeat(err).take(arity),"}]}
source_snippet:             std::iter::repeat(err).take(arity),
context_before:         let fn_sig = ty::Binder::dummy(tcx.mk_fn_sig(
context_after:             err,