syntax_data: {"ast_node_type":"variable","tokens":[{"end":66,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let expn_hash = update_disambiguator(&mut expn_data, ctx);
context_before:         debug_assert_eq!(expn_data.parent.krate, LOCAL_CRATE);
context_after:         HygieneData::with(|data| {