{"ast_node_type":"function","tokens":[{"end":97,"kind":"keyword","start":0,"text":"fn"}]}
    fn check_diagnostic_on_unimplemented(&self, attr_span: Span, hir_id: HirId, target: Target) {
    /// Checks if `#[diagnostic::on_unimplemented]` is applied to a trait definition
        if !matches!(target, Target::Trait) {