title: Flutter DART LINT Warning "Try adding an explicit type like 'dynamic', or enable implicit-dynamic in your analysis options file."
body: <p>I use a Flutter and faces the following warning with analysis_options.yaml.</p>
  <p>The following warning happens.</p>
  <blockquote>
  <p>Missing variable type for 'parsed'.
  Try adding an explicit type like 'dynamic', or enable implicit-dynamic in your analysis options file.</p>
  </blockquote>
  <p>for &quot;final parsed = ...&quot;</p>
  <blockquote>
  <p>A value of type 'dynamic' can't be returned from method 'parseEntries'
  because it has a return type of 'List'. Open documentation
  Missing parameter type for 'json'.  Try adding an explicit type like
  'dynamic', or enable implicit-dynamic in your analysis options file.</p>
  </blockquote>
  <p>for &quot;return parsed...&quot;</p>
  <pre><code>   // convert from json to class
        List&lt;Settings&gt; parseEntries(String responseBody) {
          final parsed = json.decode(responseBody).cast&lt;Map&lt;String, dynamic&gt;&gt;();
          return parsed
              .map&lt;Settings&gt;((json) =&gt; Settings.fromJsonForSaved(json))
              .toList();
        }
  </code></pre>
  <p>How can I fix this warning?</p>
  <p>flutter doctor</p>
  <pre><code>C:\src\flutter\bin\flutter.bat doctor --verbose
  [√] Flutter (Channel stable, 1.20.4, on Microsoft Windows [Version 10.0.18363.1082], locale ja-JP)
      • Flutter version 1.20.4 at C:\src\flutter
      • Framework revision fba99f6cf9 (5 days ago), 2020-09-14 15:32:52 -0700
      • Engine revision d1bc06f032
      • Dart version 2.9.2
  
  [√] Android toolchain - develop for Android devices (Android SDK version 30.0.1)
      • Android SDK at C:\Users\user\AppData\Local\Android\sdk
      • Platform android-30, build-tools 30.0.1
      • Java binary at: C:\Program Files\Android\Android Studio\jre\bin\java
      • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b01)
      • All Android licenses accepted.
  
  [√] Android Studio (version 4.0)
      • Android Studio at C:\Program Files\Android\Android Studio
      • Flutter plugin version 48.1.2
      • Dart plugin version 193.7547
      • Java version OpenJDK 
  </code></pre>