private int getIntHeaderField(int headerRelativeOffsetBytes) {
    Objects.checkIndex(headerRelativeOffsetBytes, HeaderLayout.HEADER_SIZE - Integer.BYTES + 1);
    return (int)INT32_OVER_BYTE_BUFFER.getVolatile(headerPage.rawPageBuffer(), headerRelativeOffsetBytes);
  }
private int getIntHeaderField(int headerRelativeOffsetBytes)