{"ast_node_type":"variable","tokens":[{"end":86,"kind":"keyword","start":0,"text":"let"}]}
            let niche_variants = all_indices.clone().find(|v| needs_disc(*v)).unwrap()
                |index: VariantIdx| index != largest_variant_index && !absent(&variants[index]);
                ..=all_indices.rev().find(|v| needs_disc(*v)).unwrap();