syntax_data: {"ast_node_type":"other","tokens":[{"end":16,"kind":"keyword","start":0,"text":"}"}]}
source_snippet:         } else {
context_before:             err.subdiagnostic(FeatureDiagnosticSuggestion { feature, span });
context_after:             err.subdiagnostic(FeatureDiagnosticHelp { feature });