started ex Z4

src/exercises/ex_z4/Bidder.java

@@ -0,0 +1,44 @@
+package exercises.ex_z4;
+
+import java.util.Random;
+import java.util.ArrayList;
+import java.util.List;
+
+public class Bidder implements Runnable {
+    private static int nextId = 0;
+    private final String name;
+    private final int id;
+    private final List<Item> items = new ArrayList<>();
+    private Double lastBid = null;
+
+    public Bidder(String name) {
+        this.name = name;
+        this.id = nextId++;
+    }
+
+    @Override
+    public void run() {
+        while(true){
+            Random rand = new Random();
+            double addon = rand.nextDouble(500);
+            lastBid += addon;
+        }
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public Double getLastBid() {
+        return lastBid;
+    }
+
+    @Override
+    public String toString() {
+        return "(" + id + ") " + name;
+    }
+}