Update Wall class as a Rectangle.

src/Wall.java

+import java.awt.*;
+
+public class Wall extends Rectangle {
+
+    private int x, y, width, height;
+    private Graphics2D g2d;
+    private int verOrHor;
+
+    public Wall(int x, int y, int width, int height, Graphics2D g2d,int verOrHor) {
+
+        this.x = x;
+        this.y = y;
+        this.height = height;
+        this.width = width;
+        this.g2d = g2d;
+        this.verOrHor=verOrHor;
+
+        g2d.fillRect(x, y, width, height);
+    }
+
+    public double getX() {
+        return x;
+    }
+
+    public double getY() {
+        return y;
+    }
+
+    public double getWidth() {
+        return width;
+    }
+
+    public double getHeight() {
+        return height;
+    }
+}