½ checkWindowSizeStep kotlin Unit size Int step windowedIterator collections Iterator List T iterator partialWindows Boolean reuseBuffer windowedSequence sequences Sequence@           ¦2(2(8H*" 2 (2(2(2 (2(8H&" 2(2(2 (2(8@Hò8 0 0 H 0 0 0 0 0 0¸