{"ast_node_type":"variable","tokens":[{"end":75,"kind":"keyword","start":0,"text":"let"}]}
                let seen_slices = seen.iter().filter_map(|c| c.as_slice());
            ConstructorSet::Slice { array_len, subtype_is_empty } => {
                let base_slice = Slice::new(*array_len, VarLen(0, 0));