ADD of The abstract class AbstractShape implements the Shape interface and...

ADD of The abstract class AbstractShape implements the Shape interface and provides common functionality for managing points

src/main/java/shape/AbstractShape.java

+package shape;
+
+import javafx.geometry.Point2D;
+import javafx.scene.canvas.GraphicsContext;
+import java.util.ArrayList;
+import java.util.List;
+
+public abstract class AbstractShape implements Shape {
+    protected List<Point2D> points = new ArrayList<>();
+
+    public void addPoints(Point2D... points) {
+        for (Point2D point : points) {
+            this.points.add(point);
+        }
+    }
+
+    @Override
+    public int pointsCount() {
+        return points.size();
+    }
+
+    @Override
+    public Point2D point(int index) {
+        return points.get(index);
+    }
+
+    @Override
+    public abstract void draw(GraphicsContext graphicsContext);
+}
+

src/main/java/shape/Shape.java

@@ -3,8 +3,10 @@ package shape;
 import javafx.geometry.Point2D;
 import javafx.scene.canvas.GraphicsContext;
 
+
 public interface Shape {
     int pointsCount();
     Point2D point(int index);
-    void draw(GraphicsContext context);
+    void draw(GraphicsContext graphicsContext);
 }
+