code: function(results) {
        var reg_filter = /(^用户博客|^TV talk|@comment)/;
        return _.filter(results, function(msg) {
          // Keep plain text result if it happened to exist in *results*
          // Such result is not supposed to exist but we add code here to avoid 
          // exceptions.
          if (typeof(msg) != 'object') return true;
          var qualified = !reg_filter.test(msg.title);    // filter legacy namespaces
          if (qualified) {
            var desc = msg.description;
            // Under certain circumstances, desc could be empty
            // Bypass following process
            if (desc) {
              var index = desc.indexOf('↑');
              if (index >= 0)
                msg.description = desc.substring(0, index); // filter tailing ref test
            }
          }
          return qualified;
        });
      }
docs: /*
  Do customize filtering on the results to be replied to users.
  Something happened when our site changes its default search engine.
  The result extracts will contain unexpected text and search result
  may contain pages under legacy namespace of wikia.
  We customized default behavior of the following _filter() for our own
  platform, so that this part of code is not universal applicable.