title: adding an int to a Integer List
body: <p>Inside my <code>Mappable</code> List class, I have <code>a = Integer</code> list and I want to add <code>int</code> inside this list.</p>
  
  <p>Usually <code>list.add(int)</code> will work because of java's auto boxing but I am wondering why this doesn't work for me here.</p>
  
  <p>Code explain: During construction of the <code>MappableList</code> I can pass in variable number of int parameters and I want to add them all to the Integer list</p>
  
  <pre><code>public class MappableList&lt;Integer&gt;{
  
  private final List&lt;Integer&gt; list;    
  public MappableList(int... numbers){
    list = new ArrayList&lt;Integer&gt;();  
      for(int i : numbers){
        list.add(4);
      }    
    }
  }
  </code></pre>