Unicorn.java

private static final class Unicorn
    {
        private static int mainMethodLineOfLastPatInvocation = 0;

        private static boolean pat()
        {
            boolean result = false;
            final StackTraceElement[] stackTrace = Thread.currentThread().getStackTrace();
            final StackTraceElement mainMethodInvocationPoint = stackTrace[3];
            if(mainMethodInvocationPoint.getLineNumber() != mainMethodLineOfLastPatInvocation)
            {
                result = true;
                mainMethodLineOfLastPatInvocation = mainMethodInvocationPoint.getLineNumber();
            }
            return result;
        }
    }