code: public void testEffectiveLevel(){
  {
      ErrorStatus status=new ErrorStatus("error",this);
      WarnStatus warn=new WarnStatus("warning",this);
      status.add(warn);
      assertEquals("effective level misevaluated",status.getEffectiveLevel(),Status.ERROR);
    }
  {
      InfoStatus status=new InfoStatus("info",this);
      WarnStatus warn=new WarnStatus("warning",this);
      status.add(warn);
      assertEquals("effective level misevaluated",status.getEffectiveLevel(),Status.WARN);
    }
  {
      InfoStatus status=new InfoStatus("info",this);
      WarnStatus warn=new WarnStatus("warning",this);
      ErrorStatus error=new ErrorStatus("error",this);
      status.add(warn);
      warn.add(error);
      assertEquals("effective level misevaluated",status.getEffectiveLevel(),Status.ERROR);
    }
  }
  