# System.setSecurityManager(new SecurityManager())

$ java SecurityManagerGone      (JDK 21)
    java.version = 21.0.12.1
    setSecurityManager: UnsupportedOperationException: The Security Manager is deprecated and will be removed in a future release

$ java SecurityManagerGone      (JDK 25)
    java.version = 25.0.4.1
    setSecurityManager: UnsupportedOperationException: Setting a Security Manager is not supported