{"ast_node_type":"other","tokens":[{"end":10,"kind":"keyword","start":0,"text":">,"}]}
        >,
            Item = (&'x FnArg<'tcx, M::Provenance>, &'y ArgAbi<'tcx, Ty<'tcx>>),
        callee_abi: &ArgAbi<'tcx, Ty<'tcx>>,