fun with collections

classpath/java/util/Stack.java

@@ -0,0 +1,20 @@
+package java.util;
+
+public class Stack<T> extends Vector<T> {
+  public boolean empty() {
+    return size() != 0;
+  }
+
+  public T peek() {
+    return get(size() - 1);
+  }
+
+  public T pop() {
+    return remove(size() - 1);
+  }
+
+  public T push(T element) {
+    add(element);
+    return element;
+  }
+}