private Map<Class<?>, Comparator<?>> defaultComparators = new HashMap<Class<?>, Comparator<?>>();
public MemCollectionFactory() {
BlankNodeComparator comparator = new LocalizedBlankNodeComparatorImpl(new LocalizedNodeComparatorImpl());
NodeComparator nodeComparator = new ComparatorFactoryImpl().createNodeComparator();
TripleComparator tripleComparator = new TripleComparatorImpl(nodeComparator);
TripleComparator reverseTripleComparator = new ReverseGroundedTripleComparatorImpl(tripleComparator);
defaultComparators.put(Triple.class, reverseTripleComparator);
defaultComparators.put(PredicateNode.class, nodeComparator);
defaultComparators.put(BlankNode.class, comparator);
}