Puzzle1.java

public class TestMain {
  public static void main(String[] args) {
    // What does this program print when run?
    // \u000d System.out.println("Hello ");
    System.out.println("World!");
  }
}

Puzzle1.kt

fun main(args: Array<String>) {
    // Does not work in Kotlin!
    // \u000d println("Hello ")
    println("World!")
}

See this SO question for more details why Java is behaving like that.