syntax_data: {"ast_node_type":"other","tokens":[{"end":81,"kind":"keyword","start":0,"text":"debug!(\"remove_existing:"}]}
source_snippet:             debug!("remove_existing: impl_def_id={:?} st={:?}", impl_def_id, st);
context_before:         {
context_after:             vec = self.non_blanket_impls.get_mut(&st).unwrap();