JAVA CERTIFICATION QUESTION: Using the SecurityManager class in Java

public static String getSecret(String host) {
    Permission perm = getHostPermission(host); // line n1
  
    if (distributedCache.containsKey(host)) {           
        return distributedCache.get(host); 
    }
    
    AccessController.checkPermission(perm);     // line n2

    PermissionCollection perms = perm.newPermissionCollection();
    perms.add(perm);
    
    PrivilegedAction<String> pa = new PrivilegedAction<String>() {
        public String run() {
            return getSecretFromHost(host);
        }
    };

    AccessControlContext acc = new AccessControlContext(
        new ProtectionDomain[] { 
            new ProtectionDomain(null, perms) 
        }
    );

    String secret = AccessController.doPrivileged(pa, acc); // line n3

    distributedCache.put(host, secret);
    return secret;
}