syntax_data: {"ast_node_type":"other","tokens":[{"end":77,"kind":"keyword","start":0,"text":"err.subdiagnostic(FeatureDiagnosticSuggestion"}]}
source_snippet:             err.subdiagnostic(FeatureDiagnosticSuggestion { feature, span });
context_before:         } else if let Some(span) = inject_span {
context_after:         } else {