Added pop() stub, added testPopFromHeightOneValue()

src/main/java/MyStack.java

@@ -15,6 +15,10 @@ public class MyStack {
         this.top = new Node(element, top);
     }
 
+    public Object pop() {
+        return null;
+    }
+
     private class Node {
         private Object payload;
         private int height;

src/test/java/MyStackTest.java

@@ -19,7 +19,7 @@ public class MyStackTest {
 
     private void pushDummies(int numberOfDummies) {
         for (int i=0; i<numberOfDummies; i++) {
-            stack.push(new Object());
+            stack.push(i+1);
         }
     }
 
@@ -39,4 +39,10 @@ public class MyStackTest {
         pushDummies(3);
         assertEquals(3, stack.size());
     }
+
+    @Test
+    public void testPopFromHeightOneValue() {
+        pushDummies(1);
+        assertEquals(1, stack.pop());
+    }
 }
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