title: What's the advantage of making an inner class as static with Java?
body: <p>I have an inner class in my Java class.</p>
  
  <p><img src="https://i.stack.imgur.com/mpSuW.png" alt="enter image description here"></p>
  
  <p>When I run <a href="http://findbugs.sourceforge.net" rel="noreferrer">find bugs</a>, it recommends(warns) to make it as static. </p>
  
  <p><img src="https://i.stack.imgur.com/gB3Mx.png" alt="enter image description here"></p>
  
  <p>What's the point of this warning? What's the advantage of making a inner class as static?</p>