docs: public void checkInvariant(INode node) throws InconsistentNodeModelException {
  		try {
  			doCheckInvariant(node.getRootNode());
  		} catch(ClassCastException e) {
  			throw new InconsistentNodeModelException("node has no root node", e);
  		} catch(NullPointerException e) {
  			throw new InconsistentNodeModelException("node's pointer is null", e);
  		}
  	}