message: Make AnimatedSprite event functions optional
diff: @@ -41,9 +41,9 @@ export class AnimatedSprite extends Sprite
  public animationSpeed: number;
  public loop: boolean;
  public updateAnchor: boolean;
  - public onComplete: () => void;
  - public onFrameChange: (currentFrame: number) => void;
  - public onLoop: () => void;
  + public onComplete?: () => void;
  + public onFrameChange?: (currentFrame: number) => void;
  + public onLoop?: () => void;
  private _playing: boolean;
  private _textures: Texture[];
  