syntax_data: {"ast_node_type":"other","tokens":[{"end":34,"kind":"keyword","start":0,"text":"HygieneData::with(|data|"}]}
source_snippet:         HygieneData::with(|data| {
context_before:         let expn_hash = update_disambiguator(&mut expn_data, ctx);
context_after:             let old_expn_data = &mut data.local_expn_data[self];