protected void checkDeleted() {
		if (!checkIsValid()) {
			throw new ConcurrentModificationException("Object has been deleted.");
		}
	}
Checks if this object has been deleted, in which case any use of the object is not allowed.
This method should be invoked before any modifications to the object are performed to 
ensure it still exists and is in a valid state.

@throws ConcurrentModificationException if the object has been deleted from the database.
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/DatabaseObject.java