push and pop multiple screens from container stack

android/app/src/main/java/com/reactnativenavigation/layout/ContainerStackLayout.java

 import android.view.View;
 import android.widget.FrameLayout;
 
+import java.util.Stack;
+
 public class ContainerStackLayout extends FrameLayout implements StackLayout {
 
-    private View removedView;
+    private Stack<View> backStack = new Stack<>();
 
     public ContainerStackLayout(Context context) {
         super(context);
     @Override
     public void push(View view) {
         addView(view);
-        removedView = getChildAt(0);
-        removeView(removedView);
+        backStack.push(getChildAt(0));
+        removeView(getChildAt(0));
     }
 
     @Override
     public void pop() {
-        addView(removedView);
+        addView(backStack.pop());
         removeView(getChildAt(0));
     }
 

android/app/src/test/java/com/reactnativenavigation/LayoutFactoryTest.java

         assertThat(result.getChildAt(0)).isEqualTo(otherMockView);
     }
 
+    @Test
+    public void pushTwoScreensToStackLayout() throws Exception {
+        when(reactRootViewCreator.create(eq(NODE_ID), eq(REACT_ROOT_VIEW_KEY))).thenReturn(mockView);
+        final LayoutNode container = createContainerNode();
+        final LayoutNode stackNode = createContainerStackNode(container);
+        final ContainerStackLayout containerStackLayout = (ContainerStackLayout) createLayoutFactory().create(stackNode);
+
+        View first = new View(activity);
+        pushContainer(containerStackLayout, OTHER_NODE_ID, OTHER_REACT_ROOT_VIEW_KEY, first);
+
+        View second = new View(activity);
+        pushContainer(containerStackLayout, "secondPushedScreenId", "secondPushedScreenKey", second);
+
+        ViewGroup result = (ViewGroup) TestUtils.assertViewChildrenCount(containerStackLayout, 1).get(0);
+        assertThat(result.getChildAt(0)).isEqualTo(second);
+    }
+
+    @Test
+    public void popTwoScreensFromStackLayout() throws Exception {
+        when(reactRootViewCreator.create(eq(NODE_ID), eq(REACT_ROOT_VIEW_KEY))).thenReturn(mockView);
+        final LayoutNode container = createContainerNode();
+        final LayoutNode stackNode = createContainerStackNode(container);
+        final ContainerStackLayout containerStackLayout = (ContainerStackLayout) createLayoutFactory().create(stackNode);
+
+        pushContainer(containerStackLayout, OTHER_NODE_ID, OTHER_REACT_ROOT_VIEW_KEY, new View(activity));
+        pushContainer(containerStackLayout, "secondPushedScreenId", "secondPushedScreenKey", new View(activity));
+
+        containerStackLayout.pop();
+        containerStackLayout.pop();
+
+        ViewGroup result = (ViewGroup) TestUtils.assertViewChildrenCount(containerStackLayout, 1).get(0);
+        assertThat(result.getChildAt(0)).isEqualTo(mockView);
+    }
+
+    private void pushContainer(ContainerStackLayout containerStackLayout, String screenId, String reactRootViewKey, View rootView) {
+        when(reactRootViewCreator.create(eq(screenId), eq(reactRootViewKey))).thenReturn(rootView);
+        View pushedContainer = createLayoutFactory().create(createContainerNode(screenId, reactRootViewKey));
+        containerStackLayout.push(pushedContainer);
+    }
+
     @Test
     public void popScreenFromScreenStackLayout() {
         when(reactRootViewCreator.create(eq(NODE_ID), eq(REACT_ROOT_VIEW_KEY))).thenReturn(mockView);