SortedBugCollection originator = operation.perform(result, origCollection, newCollection);
originator = operation.perform(result, origCollection, newCollection);
	public SortedBugCollection performSetOperation(SetOperation operation) {		// Create a result set which uses the version-insensitive/fuzzy bug comparator.		// This will help figure out which bug instances are the "same"		// between versions.		TreeSet<BugInstance> result = new TreeSet<BugInstance>(getComparator());				// Perform the operation, keeping track of which input BugCollection		// should be cloned for metadata.		SortedBugCollection originator = operation.perform(result, origCollection, newCollection);				// Clone the actual BugInstances selected by the set operation.		Collection<BugInstance> selected = new LinkedList<BugInstance>();		BugCollection.cloneAll(selected, result);				// Duplicate the collection from which the results came,		// in order to copy all metadata, such as analysis errors,		// class/method hashes, etc.		SortedBugCollection resultCollection = originator.duplicate();				// Replace with just the cloned instances of the subset selected by the set operation.		resultCollection.clearBugInstances();		resultCollection.addAll(selected);				return resultCollection;	}