generic stack

lib/android/app/src/main/java/com/reactnativenavigation/utils/Stack.java

+package com.reactnativenavigation.utils;
+
+public interface Stack<E> extends Iterable<E> {
+
+	void push(E element);
+
+	E pop();
+
+	E peek();
+
+	boolean remove(E element);
+
+	int size();
+
+	boolean isEmpty();
+
+}

lib/android/app/src/main/java/com/reactnativenavigation/utils/StackImpl.java

+package com.reactnativenavigation.utils;
+
+import java.util.ArrayDeque;
+
+public class StackImpl<E> extends ArrayDeque<E> implements Stack<E> {
+}

lib/android/app/src/main/java/com/reactnativenavigation/viewcontrollers/StackController.java

 import android.view.ViewGroup;
 import android.widget.FrameLayout;
 
-import java.util.ArrayDeque;
+import com.reactnativenavigation.utils.Stack;
+import com.reactnativenavigation.utils.StackImpl;
 
 public class StackController extends ViewController {
-	private ArrayDeque<ViewController> childControllers = new ArrayDeque<>();
+	private Stack<ViewController> childControllers = new StackImpl<>();
 
 	public StackController(final Activity activity) {
 		super(activity);
 		return (ViewGroup) super.getView();
 	}
 
-	public ArrayDeque<ViewController> getChildControllers() {
+	public Stack<ViewController> getChildControllers() {
 		return childControllers;
 	}