public class Shape {/*...*/}

public class Square extends Shape {/*...*/}

public class Triangle extends Shape {/*...*/}

public team class Printer {
	protected class PrintableShape playedBy Shape {
		protected String print() {
			return "Shape";
		}
	}
	protected class PrintableTriangle extends PrintableShape playedBy Triangle {
		protected String print() {
			return "Triangle";
		}		
	}
	protected class PrintableSquare extends PrintableShape playedBy Square {
		protected String print() {
			return "Square";
		}		
	}
	public String print(Shape as PrintableShape shape) {
		return shape.print();
	}
}

public class TheTest {
	final Printer printer = new Printer();
	Shape triangle = new Triangle();
	Shape square = new Square();
	
	public void run() {
		System.out.println(printer.print(triangle)); // prints Triangle
		System.out.println(printer.print(square)); // prints Square
	}
 }

public team class GermanPrinter extends Printer {
        protected class PrintableShape  {
                protected String print() {
                        return "Form";
                }
        }
        protected class PrintableTriangle  {
                protected String print() {
                        return "Dreieck";
                }               
        }
        protected class PrintableSquare {
                protected String print() {
                        return "Quadrat";
                }               
        }
}
// instantiate as
Printer printer = new GermanPrinter();