title: Cannot find reason for Redundant nullcheck of this, which is known to be non-null
body: <p>In Sonar I see a Redundant nullcheck of this, which is known to be non-null Error, but I can not find the Reason for this.</p>
  
  <p><img src="https://i.stack.imgur.com/BaPLv.png" alt="Sonar image"></p>
  
  <p>Hope somone can help me to find the reason.</p>
  
  <p>Thx &amp; Regards</p>
  
  <p>Edit1:</p>
  
  <pre><code>    public class Filter extends AbstractBaseEntity implements Serializable {
      public Filter() {
          super();
      }
  }
  </code></pre>
  
  <p>AbstractBaseEntity  has no implemented constructor</p>