HarmonyOS Path2D的addPath方法报错

// xxx.ets  
@Entry  
@Component  
struct CanvasExample {  
  private settings: RenderingContextSettings = new RenderingContextSettings(true)  
  private context: CanvasRenderingContext2D = new CanvasRenderingContext2D(this.settings)  
  build() {  
    Flex({ direction: FlexDirection.Column, alignItems: ItemAlign.Center, justifyContent: FlexAlign.Center }) {  
      Canvas(this.context)  
        .width('100%')  
        .height('100%')  
        .backgroundColor('#ffff00')  
        .onReady(() => {  
          let path = new Path2D();  
          path.moveTo(50, 5);  
          path.lineTo(20, 90);  
          path.lineTo(95, 39);  
          path.lineTo(5, 39);  
          path.lineTo(80, 90);  
          path.closePath();  
          this.context.save()  
          let testPath = new Path2D();  
          testPath.addPath(path);  
          this.context.fillStyle = '#ff0000'  
          this.context.fill(path);  
          this.context.restore()  
        })  
    }  
    .width('100%')  
    .height('100%')  
  }  
}