@Override
	void doClose(DomainObjectAdapterDB object) {
		try {
			removeDomainObject(object);
		}
		catch (LockException e) {
			throw new IllegalStateException(e);
		}
		object.getTransactionManager().close(object);
	}
Returns the undo stack depth.
(The number of items on the undo stack)
This method is for JUnits.
@return the undo stack depth
Ghidra/Framework/Project/src/main/java/ghidra/framework/data/SynchronizedTransactionManager.java