Program.java

package nmaier.so_der;

public class Program {
  static class Piece {}
  static class Man extends Piece{}
  static class Square {
    private Piece p_;
    public Square(Piece p) {
      p_ = p;
    }
    public Piece getPiece() {
      return p_;
    }
  }

  static void print(Piece piece) {
    System.out.println("Piece");
  }
  static void print(Man man) {
    System.out.println("Man");
  }
  static void print(Square square) {
    print(square.getPiece());
  }

  public static void main(String [] args) {
    Square s = new Square(new Man());
    print(s); // Prints "Piece"
  }
}