title: Can enums be subclassed to add new elements?
body: <p>I want to take an existing enum and add more elements to it as follows:</p>
  
  <pre><code>enum A {a,b,c}
  
  enum B extends A {d}
  
  /*B is {a,b,c,d}*/
  </code></pre>
  
  <p>Is this possible in Java?</p>