How to use @looker/chatty - 2 common examples

private async createIframe (url: string) {
    this._hostBuilder = Chatty.createHost(url)
    for (const eventType in this._builder.handlers) {
      for (const handler of this._builder.handlers[eventType]) {
        this._hostBuilder.on(eventType, handler)
      }
    }
    for (const attr of this._builder.sandboxAttrs) {
      this._hostBuilder.withSandboxAttribute(attr)
    }
    this._host = this._hostBuilder
      // tslint:disable-next-line:deprecation
      .frameBorder(this._builder.frameBorder)
      .withTargetOrigin(this.targetOrigin)
      .appendTo(this._builder.el)
      .build()

    // IE doesn't like calling classList.add() with no arguments, so check

beforeEach(() => {
      LookerEmbedSDK.init('host.looker.com:9999', '/auth')

      fakeDashboardClient = {}
      builder = LookerEmbedSDK.createDashboardWithUrl(testUrl)
      builder.appendTo('#the-element')
      builder.on('dashboard:run:start', () => false)
      builder.withSandboxAttr('allow-scripts')
      builder.withClassName('classy')
      client = builder.build()
      spyOn(window, 'fetch')
      spyOn(ChattyHost.prototype, 'connect').and.callFake(async function (this: any) {
        iframe = this.iframe
        return Promise.resolve({})
      })
    })