wc = _objectWrappers.wrap(_iterables.mutableListOf())
words = _objectWrappers.wrap(_arrays.arrayOf(_plugins.loadClass("java.lang.String"), "hello", "world", "kotlin"))
# 将每个单词转换为字符列表，并添加索引信息, 带索引的字符列表: [0_h, 0_e, 0_l, 0_l, 0_o, 1_w, 1_o, 1_r, 1_l, 1_d, 2_k, 2_o, 2_t, 2_l, 2_i, 2_n]
words.flatMapIndexedTo(wc, lambda index, word: _objectWrappers.wrap(word).map(
    lambda c: str(index) + "_" + c).getOrigin()).forEach(lambda it: _console.log(it))