syntax_data: {"ast_node_type":"variable","tokens":[{"end":69,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:             let expn_id = data.local_expn_data.push(Some(expn_data));
context_before:         HygieneData::with(|data| {
context_after:             let _eid = data.local_expn_hashes.push(expn_hash);