indexed stack

lib/android/app/src/main/java/com/reactnativenavigation/utils/IdStack.java → lib/android/app/src/main/java/com/reactnativenavigation/utils/IndexedStack.java

 import java.util.ArrayDeque;
 import java.util.HashMap;
 
-public class IdStack<E> {
+public class IndexedStack<K, E> {
 
-	private final ArrayDeque<String> deque = new ArrayDeque<>();
-	private final HashMap<String, E> map = new HashMap<>();
+	private final ArrayDeque<K> deque = new ArrayDeque<>();
+	private final HashMap<K, E> map = new HashMap<>();
 
-	public void push(String id, E item) {
+	public void push(K id, E item) {
 		deque.push(id);
 		map.put(id, item);
 	}
 		if (deque.isEmpty()) {
 			return null;
 		}
-		String popped = deque.pop();
+		K popped = deque.pop();
 		E removed = map.remove(popped);
 		return removed;
 	}

lib/android/app/src/test/java/com/reactnativenavigation/utils/IdStackTest.java → lib/android/app/src/test/java/com/reactnativenavigation/utils/IndexedStackTest.java

 
 import static org.assertj.core.api.Java6Assertions.assertThat;
 
-public class IdStackTest extends BaseTest {
+public class IndexedStackTest extends BaseTest {
 
-	private IdStack<Integer> uut;
+	private IndexedStack<String, Integer> uut;
 
 	@Override
 	public void beforeEach() {
 		super.beforeEach();
-		uut = new IdStack<>();
+		uut = new IndexedStack<>();
 	}
 
 	@Test