{"ast_node_type":"other","tokens":[{"end":80,"kind":"keyword","start":0,"text":"|"}]}
            | FnKind::Fn(_, _, Fn { sig, ident, generics, body: None, .. }) => {
            FnKind::Fn(FnCtxt::Foreign, _, Fn { sig, ident, generics, .. })
                self.visit_fn_header(&sig.header);