syntax_data: {"ast_node_type":"other","tokens":[{"end":61,"kind":"keyword","start":0,"text":"Some(expn_id)"}]}
source_snippet:             Some(expn_id) => self.local_expn_hashes[expn_id],
context_before:         match expn_id.as_local() {
context_after:             None => self.foreign_expn_hashes[&expn_id],