Added source files (Programmieren Tutorium)

presentations/Programmieren-Tutorium/Tutorium-10/Cage.java

@@ -0,0 +1,18 @@
+public static class Cage<T extends Animal> { 
+    private Set<T> pen = new HashSet<T>();
+
+    public void add(T animal) {
+        pen.add(animal);
+    }
+
+    /* It's OK to put subclasses into a cage of 
+       super class 
+     */
+    public void transferTo(Cage<? super T> cage) {
+        cage.pen.addAll(this.pen);
+    }
+
+    public void showAnimals() {
+        System.out.println(pen);
+    }
+}