{"ast_node_type":"impl","tokens":[{"end":73,"kind":"keyword","start":0,"text":"reveal_opaque:"}]}
        reveal_opaque: &impl Fn(OpaqueTypeKey<'tcx>) -> Option<Ty<'tcx>>,
        in_module: &impl Fn(DefId) -> Result<bool, E>,
    ) -> Result<bool, E> {