plz help me in getting the points i'am missing to find why this code does not compile?

Code:
 class SuperBase
{
}

class Base extends SuperBase
{
}

class Derived extends Base
{
}

class CovTest1
{
  public Derived getIt()
  {
   return new Derived();
  }
}

class SubCovTest2 extends CovTest1
{
  public  SuperBase getIt()
  {
     return new SuperBase();
  }

}

Last edited by shabbir; 7Mar2011 at 12:29.. Reason: Code blocks