syntax_data: {"ast_node_type":"other","tokens":[{"end":28,"kind":"keyword","start":0,"text":"latest_expns"}]}
source_snippet:                 latest_expns
context_before:             let all_expn_data: Vec<_> = HygieneData::with(|data| {
context_after:                     .map(|expn| (expn, data.expn_data(expn).clone(), data.expn_hash(expn)))