syntax_data: {"ast_node_type":"other","tokens":[{"end":60,"kind":"keyword","start":0,"text":"err.subdiagnostic(NonExhaustiveMatchAllArmsGuarded);"}]}
source_snippet:         err.subdiagnostic(NonExhaustiveMatchAllArmsGuarded);
context_before:     if !is_empty_match && all_arms_have_guards {
context_after:     }