如何在自定义组件的构建流程里跟踪组件数据或者状态，如在build里增加日志跟踪状态变量等

@Component 
struct TotalView { 
  @Prop @Watch('onCountUpdated') count: number = 0; 
  @State total: number = 0; 
  // @Watch 回调 
  onCountUpdated(propName: string): void { 
    this.total += this.count; 
  } 
 
  build() { 
    Text(`Total: ${this.total}`) 
  } 
} 
 
@Entry 
@Component 
struct CountModifier { 
  @State count: number = 0; 
 
  build() { 
    Column() { 
      Button('add to basket') 
        .onClick(() => { 
          this.count++ 
        }) 
      TotalView({ count: this.count }) 
    } 
  } 
}