{"ast_node_type":"other","tokens":[{"end":28,"kind":"keyword","start":0,"text":"fn_sig:"}]}
    fn_sig: ty::FnSig<'tcx>,
    args: Vec<FnArg<'tcx, M::Provenance>>,
    fn_abi: &'tcx FnAbi<'tcx, Ty<'tcx>>,