docs: private static long decodeDecStringToLong(int index, int len, ByteBuf buff) {
      long value = 0;
      if (len > 0) {
        int to = index + len;
        boolean neg = false;
        if (buff.getByte(index) == '-') {
          neg = true;
          index++;
        }
        while (index < to) {
          byte ch = buff.getByte(index++);
          byte nibble = (byte)(ch - '0');
          value = value * 10 + nibble;
        }
        if (neg) {
          value = -value;
        }
      }
      return value;
    }