docs: @Override
      public Object render(Map<String, Object> context, LNode... nodes) {
  
          String id = String.valueOf(nodes[0].render(context));
  
          FilterNode filter = null;
          LNode expression;
  
          if(nodes.length >= 3) {
              filter = (FilterNode)nodes[1];
              expression = nodes[2];
          }
          else {
              expression = nodes[1];
          }
  
          Object value = expression.render(context);
  
          if(filter != null) {
              value = filter.apply(value, context);
          }
  
          context.put(id, value);
  
          return "";
      }