Unicorn by stack trace inspection

gistfile1.txt

public class MagicLand {
    public static void main(String[] args) {
        for (int i = 0; i < (Math.random() * 500) + 2; i++) {
            if (Unicorn.pat()) {
                System.out.println("UNICORN #1: PAT THIS UNICORN ONCE");
            }
        }
 
        for (int i = 0; i < (Math.random() * 500) + 2; i++) {
            if (Unicorn.pat()) {
                System.out.println("UNICORN #2: PAT THIS UNICORN ONCE");
            }
        }
        System.out.println("END OF PROGRAM");
    }
 
    static class Unicorn {
 
        static Integer magicLandLine;
 
        public static boolean pat() {
            if (magicLandLine == null) {
                StackTraceElement[] trace = new Exception().getStackTrace();
                for (StackTraceElement element : trace) {
                    if (element.getClassName().equals("MagicLand")) {
                        magicLandLine = element.getLineNumber();
                        return true;
                    }
                }
            } else {
                StackTraceElement[] trace = new Exception().getStackTrace();
                for (StackTraceElement element : trace) {
                    if (element.getClassName().equals("MagicLand") && magicLandLine != element.getLineNumber()) {
                        magicLandLine = element.getLineNumber();
                        return true;
                    }
                }
            }
            return false;
        }
    }
}