title: iterate in a multilist provider
body: <p>I fetch a future from DB, a List&lt;List&gt; ...each sublist contains 3 variables.</p>
  <p>I assign the list to a provider.</p>
  <pre><code>  class SomeProvider with ChangeNotifier{
       List&lt;List&lt;dynamic&gt;?&gt;? _fetchedDataList;
       String? _one;
       String? _two;
       String? _three; 
    }
  
   List&lt;List&lt;dynamic&gt;?&gt;?  get fetchedDataList =&gt; _fetchedDataList;
   String? get first =&gt; _first;
   String? get one =&gt; _one;
   String? get two =&gt; _two;
   String? get three =&gt; _three;
  
  void setFetchedDataList(List&lt;List&lt;dynamic&gt;?&gt;? theList){
     _fetchedDataList = theList;
  }
  
  void setOne(String? one){
   _one = one;
  }
  </code></pre>
  <p>in the widget I set the provider :</p>
  <pre><code> providerClass = Provider.of&lt;SomeProvider&gt;(context);
   
   queryDB.then(theFutureResult){
    providerClass.setFetchedDataList(theFutureResult); 
   }
  </code></pre>
  <p>Now...how to iterate through the fetchedDataList to get the values of the variables for each sub list ? cuz I need assign each 3 variables in separate Container's texts the provider get method of each variable.</p>