title: Java - Add an instance of an abstract class in another instance
body: <p>I have this piece of code :</p>
  
  <pre><code>public class Profile extends Container{
      public Profile(String value) {
          Container profilo_1 =new Container();
          Container profilo_2 =new Container();
  
          // (1) THIS ADD A BUTTON TO THE MAIN CLASS
          this.createButton().setLabel("Modifica Profilo");
  
          // (2) NOW I NEED TO ADD A BUTTON INTO THE INSTANCE OF profilo_2 BUT IT FAILS
          profilo_2.add(this.createButton());
  
          this.add(profilo_1);
          this.add(profilo_2);        
      }
  }
  </code></pre>
  
  <p>the point (2) fails, because it said that im about to adding a child to this container, but it is owner already by a container...</p>
  
  <p>In fact, if i do this :</p>
  
  <pre><code>ILabel label=new ILabel();
  profilo_2.add(label);
  </code></pre>
  
  <p>it said to me that ILabel() is abract and cannot be instantiated!</p>
  
  <p>How can I fix it? Cheers to everybody :)</p>