add method draw

src/main/java/shape/Decorator.java

 package shape;
 
 import javafx.geometry.Point2D;
+import javafx.scene.canvas.GraphicsContext;
 
 public abstract class Decorator implements Shape {
     protected Shape decoratedShape;
@@ -17,4 +18,9 @@ public abstract class Decorator implements Shape {
     public Point2D point(int index) {
         return decoratedShape.point(index);
     }
+
+    @Override
+    public void draw(GraphicsContext graphicsContext) {
+        decoratedShape.draw(graphicsContext);
+    }
 }