{"ast_node_type":"variable","tokens":[{"end":39,"kind":"keyword","start":0,"text":"let"}]}
                    let mut tail_mask =
                    debug_assert!(num_words > 0 && num_words <= CHUNK_WORDS);
                        1 << (*other_chunk_domain_size - ((num_words - 1) * WORD_BITS) as u16) - 1;