syntax_data: {"ast_node_type":"other","tokens":[{"end":77,"kind":"keyword","start":0,"text":"debug!(\"remove_existing:"}]}
source_snippet:             debug!("remove_existing: impl_def_id={:?} st=None", impl_def_id);
context_before:         } else {
context_after:             vec = &mut self.blanket_impls;