private long getLongField(final int recordId,
                            final int fieldRelativeOffset) throws IOException {
    final long recordOffsetInFile = recordOffsetInFile(recordId);
    final int recordOffsetOnPage = storage.toOffsetInPage(recordOffsetInFile);
    try (final PageUnsafe page = (PageUnsafe)storage.pageByOffset(recordOffsetInFile, /*forWrite: */ false)) {
      page.lockPageForRead();
      try {
        final ByteBuffer pageBuffer = page.rawPageBuffer();
        return pageBuffer.getLong(recordOffsetOnPage + fieldRelativeOffset);
      }
      finally {
        page.unlockPageForRead();
      }
    }
  }
private long getLongField(final int recordId,
                            final int fieldRelativeOffset)