title: set back button title text in iOS Xamarin
body: <p>I want to set the BackButton Title text to ""(means empty). I am using below code to set the Title but it is not working.</p>
  
  <p><strong>Try 1 :</strong> </p>
  
  <pre><code>this.NavigationItem.BackBarButtonItem = new UIBarButtonItem("", UIBarButtonItemStyle.Plain, null);
  </code></pre>
  
  <p><strong>Try 2 :</strong></p>
  
  <pre><code>this.NavigationItem.BackBarButtonItem.Title = "";
  </code></pre>
  
  <p>it is give the <code>object is not set to instance</code>.</p>
  
  <p>Is there any way to set the Back button title null in iOS.</p>
  
  <p>Any Help Will be Appreciated.</p>