/**
  * Return the model provider for this content provider.
  *
  * @return the model provider for this content provider
  */
 protected final ModelProvider getModelProvider() {
   try {
     return ModelProvider.getModelProviderDescriptor(getModelProviderId()).getModelProvider();
   } catch (CoreException e) {
     // TODO: this is a bit harsh. can we do something less destructive
     throw new IllegalStateException();
   }
 }