syntax_data: {"ast_node_type":"function","tokens":[{"end":65,"kind":"keyword","start":0,"text":"pub"}]}
source_snippet:     pub fn schedule_expn_data_for_encoding(&self, expn: ExpnId) {
context_before:     /// Record the fact that we need to serialize the corresponding `ExpnData`.
context_after:         if !self.serialized_expns.lock().contains(&expn) {