started ex Z4

src/exercises/ex_w/TestingExchanger_Garage.java

@@ -0,0 +1,12 @@
+package exercises.ex_w;
+
+public class TestingExchanger_Garage {
+    String[] carTypes = {"Seat Alhambra", "BMW Mini", "Tesla 3"};
+    public static void main(String[] args) {
+        // Create a Customer thread and a Garage thread
+        // that use an exchanger for replacing the customer car
+        // with a courtesy car during the reparation. At the end of the day,
+        // the cars are exchanged back.
+        Garage garage = new Garage();
+    }
+}