@Override
	public long getFileBytesOffset() {
		if (subBlock instanceof FileBytesSubMemoryBlock) {
			return ((FileBytesSubMemoryBlock) subBlock).getFileBytesOffset();
		}
		return -1;
	}
Class for describing the source of bytes for a memory block.
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/mem/MemoryBlockSourceInfoDB.java