title: Missing concrete implementation 'getter Equatable' / issue with props
body: <p>I am working through many of the tutorials out there on bloc with flutter and running into some inconsistencies.  </p>
  
  <p>I am using Android studio and creating the bloc code by using the plugin from Intellij v1.6.0.</p>
  
  <p>For the bloc_event, I continue to see examples that look like this.</p>
  
  <pre><code>@immutable
  abstract class FruitEvent extends Equatable {
    FruitEvent([List props = const []]) : super(props);
  }
  </code></pre>
  
  <p>When I generate my bloc files and look at the initial _event one that generates, it looks like this.</p>
  
  <pre><code>@immutable
  abstract class SongEvent extends Equatable {
    const SongEvent();
  }
  </code></pre>
  
  <p>If I modify my code that is generated to include the following...</p>
  
  <pre><code>[List props = const []]) : super(props)
  </code></pre>
  
  <p>Then I get the following error "Too many positional arguments, 0 expected, 1 found" which references props at the end of the line shown above.</p>
  
  <p>If I leave my code as it was generated by the bloc plugin, and then try to implement my events by adding in the following...</p>
  
  <pre><code>class AddSong extends SongEvent {}
  </code></pre>
  
  <p>Then I get an error of "Missing concrete implementation of 'getter Equatable.props'</p>
  
  <p>Here is my current bloc/song_event.dart</p>
  
  <pre><code>import 'package:equatable/equatable.dart';
  import 'package:meta/meta.dart';
  
  @immutable
  abstract class SongEvent extends Equatable {
    const SongEvent();
  }
  
  class AddSong extends SongEvent {}
  </code></pre>
  
  <p><strong>Question</strong>
  Should I be using the line that has props in it as shown in the FuitEvent example?</p>
  
  <p>I don't understand what it is I am missing here and why it shows with an error when I try to use the same method as shown in so many of the tutorials.</p>