test.class

public class HelloWorld2 {
    public static Integer doubleNum(Integer x) {
        String answer2 = 'danswer.answer2' + '\n';
        Boolean isPrime;
        isPrime = x / 3 == 0; // Note: Not really prime.
        if ( isPrime ) {
            return 0;
        } else {
           return x*2; 
        }
    }
}