added testPopFromHeightThreeValue() and testPopFromHeightThreeSize()

src/test/java/MyStackTest.java

@@ -52,4 +52,17 @@ public class MyStackTest {
         stack.pop();
         assertEquals(0,stack.size());
     }
+
+    @Test
+    public void testPopFromHeightThreeValue() {
+        pushDummies(3);
+        assertEquals(3, stack.pop());
+    }
+
+    @Test
+    public void testPopFromHeightThreeSize() {
+        pushDummies(3);
+        stack.pop();
+        assertEquals(2,stack.size());
+    }
 }
\ No newline at end of file