syntax_data: {"ast_node_type":"function","tokens":[{"end":83,"kind":"keyword","start":0,"text":"fn"}]}
source_snippet:     fn visit_local(&mut self, local: &mut Local, ctxt: PlaceContext, _: Location) {
context_before:     #[tracing::instrument(level = "trace", skip(self))]
context_after:         let new_local = self.copy_classes[*local];