docs: public long getSize() {
          long size = isParsed ? getContentSize() : content.limit();
          size += (8 + // size|type
                  (size >= ((1L << 32) - 8) ? 8 : 0) + // 32bit - 8 byte size and type
                  (UserBox.TYPE.equals(getType()) ? 16 : 0));
          size += (deadBytes == null ? 0 : deadBytes.limit());
          return size;
      }