public class Nullable {
	public static void main( String[] args ) {
		// String! str = "hello";
		// String? opt = ( Math.random() < 0.5 ? "world" : null );
		String opt = ( Math.random() < 0.5 ? "world" : null );
		System.out.println( "hello world" );
	}
}

// > javac --enable-preview --release 23 Nullable.java 
// > java Nullable 
// < hello world

// https://openjdk.org/jeps/8303099
// https://openjdk.org/jeps/12
// https://openjdk.org/projects/jdk/23/
// https://openjdk.org/projects/jdk/24/
// https://openjdk.org/projects/jdk/25/
// https://docs.oracle.com/en/java/javase/21/docs/api/preview-list.html
// https://docs.oracle.com/en/java/javase/22/docs/api/preview-list.html
// https://docs.oracle.com/en/java/javase/23/docs/api/preview-list.html