{"ast_node_type":"variable","tokens":[{"end":74,"kind":"keyword","start":0,"text":"let"}]}
        let msg = self.subdiagnostic_message_to_diagnostic_message(label);
    pub fn span_label(&mut self, span: Span, label: impl Into<SubdiagMessage>) -> &mut Self {
        self.span.push_span_label(span, msg);