title: Empty List of String appears null when initialized
body: <p>I am trying to insert a string into my list of strings. </p>
  
  <p>I initialize my string like so in a class called globals that holds this list.</p>
  
  <p><code>List&lt;String&gt; myStringList = [];</code></p>
  
  <p>Then in my controller class I am trying to insert a string into the list like so.</p>
  
  <p><code>globals.myStringList.add(stringToAdd);</code></p>
  
  <p>But I get an error that says the list is null. Not sure if I am initializing it wrong since it appears this is the way to initialize an empty list.</p>
  
  <p>Globals Class</p>
  
  <pre><code>import 'package:flutter_project/models/categories.dart';
  import 'package:flutter_project/models/videos.dart';
  List&lt;String&gt; reports = [];
  List&lt;Video&gt; videos = [];
  List&lt;Category&gt; categories = [];
  List&lt;String&gt; userSearches = &lt;String&gt;[];
  bool inSearch = false;
  </code></pre>