title: Java: adding a new method to the interface List<E>
body: <p>Is there possible to add a new custom method to the well-known interface List in a way in Java? I tried to implement List interface to "public abstract class MyList", however, I would like to achieve it remaining the same name of the interface "List". For example, later implememnt in the following way:</p>
  
  <pre><code>List mylist = new ArrayList();
  mylist.newmethod();
  </code></pre>