104 of 234 Test passing

src/main/java/rocks/zipcode/io/quiz4/generics/MyStack.java

@@ -1,25 +1,36 @@
 package rocks.zipcode.io.quiz4.generics;
 
+import java.util.Iterator;
+import java.util.Stack;
+
 /**
  * @author leon on 11/12/2018.
  */
-public class MyStack<SomeType> {
+public class MyStack<SomeType> implements Iterable{
+
+    Stack<SomeType> stack = new Stack<>();
+
     public MyStack() {
-        throw new UnsupportedOperationException("Method not yet implemented");
     }
 
     public Boolean isEmpty() {
-        return null;
+        return stack.isEmpty();
     }
 
     public void push(SomeType i) {
+        stack.push(i);
     }
 
     public SomeType peek() {
-        throw new UnsupportedOperationException("Method not yet implemented");
+        return stack.peek();
     }
 
     public SomeType pop() {
-        return null;
+        return stack.pop();
+    }
+
+    @Override
+    public Iterator iterator() {
+        return stack.iterator();
     }
 }

src/main/java/rocks/zipcode/io/quiz4/generics/SortedGroup.java

@@ -4,15 +4,19 @@ package rocks.zipcode.io.quiz4.generics;
  * @author leon on 18/12/2018.
  */
 public class SortedGroup<_> extends Group<_> {
+
     @Override
     public void insert(_ value) {
+        super.group.add(value);
     }
 
     @Override
     public void delete(_ value) {
+        super.group.remove(value);
     }
 
     public Integer indexOf(_ firstValue) {
-        return null;
+        return super.group.indexOf(firstValue);
     }
+
 }