code: public long getAlignedSizeOfRaw() {
          long sizeOfRaw = get(SIZE_OF_RAW_DATA);
          if (sizeOfRaw == (sizeOfRaw & ~0xfff)) {
              return sizeOfRaw;
          }
          long result = (sizeOfRaw + 0xfff) & ~0xfff;
          assert result % 4096 == 0;
          return result;
      }
docs: Returns the SizeOfRawData rounded up to a multiple of 4kb.
  
  @return aligned SizeOfRawData