{"ast_node_type":"import","tokens":[{"end":84,"kind":"keyword","start":0,"text":"//"}]}
    // We want to make sure we have the ctxt set so that we can use unstable methods
fn show_substructure(cx: &ExtCtxt<'_>, span: Span, substr: &Substructure<'_>) -> BlockOrExpr {
    let span = cx.with_def_site_ctxt(span);