public synchronized boolean isChanged() {
		return currentCheckpoint != 0 || currentCheckpointHead != null || hasNonUndoableChanges;
	}
@return true if unsaved "buffer" changes exist.
If no changes have been made, or all changes have been
"undone", false will be returned.  Parameter changes
are no considered.
Ghidra/Framework/DB/src/main/java/db/buffers/BufferMgr.java