title: How to replace deprecated List
body: <p>List has been deprecated. How do I re-write the following code?</p>
  <pre><code>  RosterToView.fromJson(Map&lt;String, dynamic&gt; json) {
      if (json['value'] != null) {
        rvRows = new List&lt;RVRows&gt;();
        json['value'].forEach((v) {
          rvRows.add(new RVRows.fromJson(v));
        });
      }
    }
  </code></pre>