title: Private interface methods are supported
body: <p><a href="http://openjdk.java.net/jeps/213" rel="noreferrer">Private interface methods are supported by Java 9.</a></p>
  
  <p>This support allows non-abstract methods of an <code>interface</code> to share code between them. Private methods can be static or instance.</p>
  
  <p>Can private methods of an interface be <code>abstract</code> or <code>default</code>?</p>
  
  <p>May I ask for an example where "<code>private static</code> interface methods" are useful in terms of code?</p>