{"ast_node_type":"other","tokens":[{"end":67,"kind":"keyword","start":0,"text":"debug_assert!(ref_pat_matches_mut_ref);"}]}
                            debug_assert!(ref_pat_matches_mut_ref);
                            // the same error as the old-Edition version below.
                            self.error_inherited_ref_mutability_mismatch(pat, pat_prefix_span);