NodeList t = r.eval(docs, null, null).getNodeList();
NodeList t = r.eval(context, docs, null, null).getNodeList();
  public Value eval(DocumentSet docs, NodeSet context, NodeProxy node) {	  NodeSet result = new ArraySet(10);      for(Iterator i = returnList.iterator(); i.hasNext(); ) {		  Expression r = (Expression)i.next();		  NodeList t = r.eval(docs, null, null).getNodeList();		  result.addAll(t);      }      return new ValueNodeSet(result);  }