docs: static byte[] encode(int count) {
          // 计算需要填充的位数
          int amountToPad = BLOCK_SIZE - (count % BLOCK_SIZE);
          if (amountToPad == 0) {
              amountToPad = BLOCK_SIZE;
          }
          // 获得补位所用的字符
          char padChr = chr(amountToPad);
          String tmp = new String();
          for (int index = 0; index < amountToPad; index++) {
              tmp += padChr;
          }
          return tmp.getBytes(CHARSET);
      }