code: private static void zipSize2KBuffer(
        final Object[] bufA, final int startA, // input
        final Object[] bufC, final int startC, // output
        final int k) {
      final int randomOffset = ItemsSketch.rand.nextBoolean() ? 1 : 0;
      final int limC = startC + k;
      for (int a = startA + randomOffset, c = startC; c < limC; a += 2, c++) {
        bufC[c] = bufA[a];
      }
    }
docs: note: this version refers to the ItemsSketch.rand