message: types(ImagePreview): swipeTo should be optional
diff: @@ -20,9 +20,9 @@ export type ImagePreviewOptions =
  closeOnPopstate?: boolean;
  closeIconPosition?: string;
  getContainer?: string | (() => Element);
  - onClose?: () => void;
  - onChange?: (index: number) => void;
  - swipeTo(index: number, options?: SwipeToOptions): void;
  + onClose?(): void;
  + onChange?(index: number): void;
  + swipeTo?(index: number, options?: SwipeToOptions): void;
  };
  export class VanImagePreview extends VanPopupMixin {
  