如题。例如如下代码使用Vue.js装饰器进行编写，期望从id为`the-canvas`的`<canvas>`元素里拿到 `context`；代码编辑器为VSCode

import { Vue, Component } from 'vue-property-decorator'

@Component
export default class BizPage extends Vue {
  private canvasCtx: CanvasRenderingContext2D | null = null
  private async setCanvasCtx() {
    const canvasEl = document.querySelector('#the-canvas') as HTMLCanvasElement
    const width = canvasEl.width
    const height = canvasEl.height
    const canvasDomNode = await canvasEl?.$$prepare() as HTMLCanvasElement
    const ctx = canvasDomNode.getContext('2d') as CanvasRenderingContext2D
    const dpr = wx.getSystemInfoSync().pixelRatio //获取设备像素比
    canvasEl.width = width * dpr
    canvasEl.height = height * dpr
    ctx.scale(dpr, dpr)

    this.canvasCtx = ctx
    console.log(this.canvasCtx)
  }
}

代码编写过程中，`canvasEl?.$$prepare()` Typescript会报错，提示：“Property '$$prepare' does not exist on type 'HTMLCanvasElement'.”，但实际可正常运行。

因此，在这里，canvasEl的类型应当是什么？kbone中对此有没有对应的Typescript定义？