@Test
public void invalidateSessions()
{

    Date currentDate = DateUtils.addMinutes(session.getStartDate(), sessionManager.getSessionTimeout());
    System.out.println( "Session Time:" + session.getEndDate() + "\nCurrentTime:"+ currentDate);
    assertTrue( session.getEndDate().getTime() <= currentDate.getTime() );
    sessionManager.invalidateSessions( currentDate );
    assertNull( sessionManager.getValidSession(sessionId));
}