title: Error: The superclass, 'Bloc', has no unnamed constructor that takes no arguments. class OverViewListBloc extends Bloc<OListEvent, List<OList>> {
body: <p>Why did this error occur?:</p>
  <pre><code>Error: The superclass, 'Bloc', has no unnamed constructor that takes no arguments.
  class OverViewListBloc extends Bloc&lt;OListEvent, List&lt;OList&gt;&gt; {
  </code></pre>
  <p>I could fix it with <code>OverViewListBloc(List&lt;OList&gt; initialState) : super(initialState);</code>, but I don't want to fix it this way, because I have to give an argument.</p>
  <p>This is my code:</p>
  <pre><code>class OverViewListBloc extends Bloc&lt;OListEvent, List&lt;OList&gt;&gt; {
    OverViewListBloc(List&lt;OList&gt; initialState) : super(initialState);
  
    List&lt;OList&gt; get initialState =&gt; List&lt;OList&gt;();
  
    @override
    Stream&lt;List&lt;OList&gt;&gt; mapEventToState(OListEvent event) async* {
      if (event is SetList) {
        yield event.foodList;
      } else if (event is AddList) {
        List&lt;OList&gt; newState = List.from(state);
        if (event.newolist != null) {
          newState.add(event.newolist);
        }
        yield newState;
      } else if (event is DeleteList) {
        List&lt;OList&gt; newState = List.from(state);
        newState.removeAt(event.olistindex);
        yield newState;
      } else if (event is UpdateList) {
        List&lt;OList&gt; newState = List.from(state);
        newState[event.listIndex] = event.newolist;
        yield newState;
      }
    }
  }
  </code></pre>
  <p>Is there any other fix?</p>