message: Fix ad meta default.
diff: @@ -12,7 +12,7 @@ import AppAdWidgetInner from './inner.vue';
  export default class AppAdWidget extends Vue {
  @Prop(propOptional(String, 'rectangle')) size!: AdSlotSize;
  @Prop(propOptional(String, 'content')) placement!: AdSlotPlacement;
  - @Prop(propOptional(Object, () => {})) meta!: AdSlotMeta;
  + @Prop(propOptional(Object, () => ({}))) meta!: AdSlotMeta;
  adSlot: AdSlot = null as any;
  