code: public static Node getJcrNode(final FedoraResource resource) {
          if (resource instanceof FedoraResourceImpl) {
              return ((FedoraResourceImpl)resource).getNode();
          }
          throw new IllegalArgumentException("FedoraResource is of the wrong type");
      }
docs: Retrieve the underlying JCR Node from the FedoraResource
  
  @param resource the Fedora resource
  @return the JCR Node