AssertNullable.java

public class AssertNullable {
    public static void main(String[] args) {
        if (args.length >= 1) {
            Boolean b = null;
            // This will result in an NPE, not an AssertionError:
            // Exception in thread "main" java.lang.NullPointerException
            // Therefore, the Nullness Checker warns about this.
            //:: error: (condition.nullable)
            assert b;
        } else {
            String s = null;
            // This is OK, the message will look like:
            // Exception in thread "main" java.lang.AssertionError: null
            assert 4 < 3 : s;
        }
    }

    void foo() {
        String s = 3 > 2 ? null : "ba";
        //:: error: (dereference.of.nullable)
        assert s.hashCode() > 4;
    }
}