code: protected boolean checkForSignIn() {
  		 Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
  		 if ((authentication != null) && authentication.isAuthenticated()) {
  			 LOG.debug("Security context contains CAS authentication");
  			 return true;
  		} 
  		
  		return false;
  	 }
docs: used in NextServerApplication.addSecurityStrategy