{"ast_node_type":"other","tokens":[{"end":47,"kind":"keyword","start":0,"text":"#[allow(rustc::diagnostic_outside_of_impl)]"}]}
    #[allow(rustc::diagnostic_outside_of_impl)]
    /// Add a span label to the arguments of the closure, if it exists.
    pub(super) fn args_subdiag(self, err: &mut Diag<'_>, f: impl FnOnce(Span) -> CaptureArgLabel) {