code: public void testAddStatus(){
  {
      InfoStatus status=new InfoStatus("testing",this);
      status.add(new ErrorStatus("error",this));
      Iterator it=status.iterator();
      assertTrue("No status was added",it.hasNext());
      assertTrue("hasChilden method reported wrong result",status.hasChildren());
    }
  {
      InfoStatus status=new InfoStatus("testing",this);
      try {
        status.add(null);
        fail("method should have thrown an Exception");
      }
   catch (    NullPointerException ex) {
      }
    }
  }
  