Function<EObject, String> idFunction = new Function<EObject, String>()
      {
         public String apply(EObject input)
         {
            if (input instanceof AbstractBlock)
            {
               return ((AbstractBlock) input).getName();
            }
            // a null return here tells the match engine to fall back to the other matchers
            return null;
         }
      };
      
      IMatchEngine.Factory.Registry registry = EMFCompareRCPPlugin.getDefault().getMatchEngineFactoryRegistry();
      /*
       * configure our matching engine
       */
      IEObjectMatcher fallBackMatcher = DefaultMatchEngine.createDefaultEObjectMatcher(UseIdentifiers.NEVER);
      IEObjectMatcher customIDMatcher = new IdentifierEObjectMatcher(fallBackMatcher, idFunction);
      IComparisonFactory comparisonFactory = new DefaultComparisonFactory(new DefaultEqualityHelperFactory());
      final MatchEngineFactoryImpl matchEngineFactory = new MatchEngineFactoryImpl(customIDMatcher, comparisonFactory);
      matchEngineFactory.setRanking(20); // default engine ranking is 10, must be higher to override.
      registry.add(matchEngineFactory);