title: What is initState and super.initState in flutter?
body: <p>In the documentation it is written but I am not able to understand it.</p>
  <blockquote>
  <p>Called when this object is inserted into the tree.</p>
  <p>The framework will call this method exactly once for each State object it creates.</p>
  <p>Override this method to perform initialization that depends on the location at which this object was inserted into the tree (i.e., context) or on the widget used to configure this object (i.e., widget).</p>
  <p>If a State's build method depends on an object that can itself change state, for example a ChangeNotifier or Stream, or some other object to which one can subscribe to receive notifications, then the State should subscribe to that object during <strong>initState</strong>, unsubscribe from the old object and subscribe to the new object when it changes in didUpdateWidget, and then unsubscribe from the object in dispose.</p>
  <p>You cannot use BuildContext.inheritFromWidgetOfExactType from this method. However, didChangeDependencies will be called immediately following this method, and BuildContext.inheritFromWidgetOfExactType can be used there.</p>
  <p>If you override this, make sure your method starts with a call to <code>super.initState()</code>.</p>
  </blockquote>
  <p>But I'm not sure about its meaning. Can you explain it?</p>