constructor () {
    super()

    this[kState] = 'empty'
    this[kResult] = null
    this[kError] = null
    this[kEvents] = {
      loadend: null,
      error: null,
      abort: null,
      load: null,
      progress: null,
      loadstart: null
    }
  }
@see https://w3c.github.io/FileAPI/#readAsBinaryString
@param {import('buffer').Blob} blob