{"ast_node_type":"other","tokens":[{"end":67,"kind":"keyword","start":0,"text":"provided_arg_tys:"}]}
        provided_arg_tys: &IndexVec<ProvidedIdx, (Ty<'tcx>, Span)>,
        matched_inputs: &IndexVec<ExpectedIdx, Option<ProvidedIdx>>,
        formal_and_expected_inputs: &IndexVec<ExpectedIdx, (Ty<'tcx>, Ty<'tcx>)>,