title: How to put in the ui thread the data from the list of lists Flutter?
body: <p>I am trying to put the lists of lists in the ui thread, but i am confised how to do that properly. I am trying to put widgets in the map method and got the error:</p>
  <pre><code>1. The element type 'List&lt;Text&gt;' can't be assigned to the list type 'Widget'
  </code></pre>
  <p>How can I avoid this error if I need to present data from the lists of lists at the same time?</p>
  <pre><code>List&lt;Common&gt; common = merge(buying, bait, tackle).toList();
      return Scaffold(
        appBar: AppBar(),
        body: Column(
          children: &lt;Widget&gt;[
            common[index].fishingTackle.map((e) =&gt; Text(e.name)),
            common[index].fishBait.map((e) =&gt; Text(e.baitName)),
            common[index].time.toString()),
          ],
        )
      );
    }
  }
  
   Iterable&lt;Common&gt; merge(List&lt;TimeByuing&gt; buying, List&lt;FishBait&gt; bait,
          List&lt;FishingTackle&gt; tackle) sync* {
        for (int i = 0; i &lt; buying.length; i++) {
          var fishingTackle = tackle.where((v) =&gt; v.id == buying[i].id).toList();
          var fishBait = bait.where((v) =&gt; v.typeId == buying[i].typeId).toList();
          yield Common(
            id: buying[i].id,
            typeId: buying[i].typeId,
            fishingTackle: fishingTackle,
            fishBait: fishBait,
            time: buying[i].time,
          );
        }
      }
  </code></pre>