Creates new objects by cloning an existing object (the prototype) instead of building from scratch.

Useful when object creation is costly and objects share most of their state.

class Shape {
  String color;
  double x, y;

  Shape(this.color, this.x, this.y);

  Shape clone() => Shape(color, x, y);
}

// Usage
final original = Shape('red', 10, 20);
final copy = original.clone()..color = 'blue';