{"ast_node_type":"other","tokens":[{"end":94,"kind":"keyword","start":0,"text":"(ConstraintCategory::Return(kind),"}]}
            (ConstraintCategory::Return(kind), true, false) if self.is_closure_fn_mut(fr) => {
        let mut diag = match (category, fr_is_local, outlived_fr_is_local) {
                self.report_fnmut_error(&errci, kind)