Finished part 1, commented out Arrays.java to make tests work

src/main/java/Pair/Arrays.java

@@ -10,7 +10,7 @@ import java.util.Collections;
  * A max method that returns the largest item in the arraylist
  * And a minmax method that returns a pair containing the largest and smallest items from the array list
  */
-public class Arrays {
-    public static <___> Pair<E> firstLast(ArrayList<___> a) {
-    }
-}
+//public class Arrays {
+//    public static <___> Pair<E> firstLast(ArrayList<___> a) {
+//    }
+//}

src/main/java/StackArrayList/Stack.java

@@ -8,8 +8,25 @@ import java.util.ArrayList;
  */
 public class Stack<E> {
     private ArrayList elements;
-    
+
     public Stack(){
+        this.elements = new ArrayList<E>();
+    }
+
+    public E push(E item) {
+        this.elements.add(item);
+        return item;
+    }
+
+    public E pop() {
+        return (E) this.elements.remove(elements.size() - 1);
+    }
 
+    public boolean isEmpty() {
+        if (this.elements.size() == 0) {
+            return true;
+        } else {
+            return false;
+        }
     }
 }