{"ast_node_type":"other","tokens":[{"end":84,"kind":"keyword","start":0,"text":"mbe::TokenTree::MetaVarDecl"}]}
        mbe::TokenTree::MetaVarDecl { name, kind, .. } => format!("${name}:{kind}"),
        mbe::TokenTree::MetaVar(_, name) => format!("${name}"),
        _ => panic!(