public class Application {
    public static void main(String[] args) {
        // Uncommenting this line fixes the issue by triggering MyIssue.<clinit>
        // System.out.println(MyIssue.schema);

        System.out.println(MyIssue.A.schema); // prints "aa"
        System.out.println(MyIssue.schema); // prints "null" (!!)
    }
}