code: function extendInstance(ctx) {
    // 适配微信小程序属性
    if (!this.properties) {
      Object.defineProperty(this, 'properties', {
        get() {
          return this.props
        }
      })
  
      defineProperty(this, 'createSelectorQuery', () => createSelectorQuery({
        context: this
      }))
  
      defineProperty(this, 'triggerEvent', triggerEvent)
  
      Object.defineProperty(this, 'id', {
        get() {
          return this.props.id || this.$id
        }
      })
  
      defineProperty(this, 'selectAllComponents', selectAllComponents)
  
      defineProperty(this, 'selectComponent', selectComponent)
  
      cannotAchieveComponentInstanceFunctions(this);
    }
  }
docs: 扩展实例属性
  @param {*} ctx