如何在运行时更改Angular CDK overlay的dir属性？

import { Overlay, OverlayRef } from '@angular/cdk/overlay';
import { Directionality } from '@angular/cdk/bidi';

constructor(private overlay: Overlay, private directionality: Directionality) { }

const overlayRef = this.overlay.create(this.getOverlayConfig());

private getOverlayConfig(): OverlayConfig {
  const positionStrategy = this.overlay.position().global().centerHorizontally().centerVertically();
  const overlayConfig = new OverlayConfig({ positionStrategy, hasBackdrop: true, scrollStrategy: this.overlay.scrollStrategies.block() });
  overlayConfig.direction = this.directionality.value;
  return overlayConfig;
}

this.directionality.change.subscribe(() => {
  overlayRef.getConfig().direction = this.directionality.value;
  overlayRef.updatePosition();
});