@Override
      public Comparable<?> getMatchId(EObject element_p, IModelScope scope_p) {
        InternalEObject scopeRoot = ((InternalEObject)((SubtreeModelScope) scope_p).getRoot());
        InternalEObject internalElement = (InternalEObject)element_p;
        List<String> uriFragmentPath = new ArrayList<String>();
        HashSet<InternalEObject> visited = new HashSet<InternalEObject>();
        for (InternalEObject container = internalElement.eInternalContainer(); container != scopeRoot.eContainer() && visited.add(container); container = internalElement.eInternalContainer()) {
          uriFragmentPath.add(container.eURIFragmentSegment(internalElement.eContainingFeature(), internalElement));
          internalElement = container;
        }
        // we incrust the element's class name into the comparable to only match elements of the same type
        StringBuffer result = new StringBuffer(element_p.eClass().getName() + "#//");
        for (int i = uriFragmentPath.size() - 1; i >= 0; --i) {
          result.append('/');
          result.append(uriFragmentPath.get(i));
        }
        return result.toString();
      }
	  };