ZT Magical Java Puzzle: “Pat The Unicorns” solution

gistfile1.java

public class Unicorn {

  private static String line;

	public static boolean pat() {
		StackTraceElement[] stackTrace = Thread.currentThread().getStackTrace();
		if (line == null) {
			line = stackTrace[2].toString().split(":")[1];
			return true;
		} else if (!line.equals(stackTrace[2].toString().split(":")[1])) {
            line = stackTrace[2].toString().split(":")[1];
			return true;
		} else {
			return false;
		}
	}
}