docs: async function asyncActPolyfill(cb) {
    // istanbul-ignore-next
    if (
      !youHaveBeenWarned &&
      actSupported &&
      reactDomSixteenPointNineIsReleased
    ) {
      // if act is supported and async act isn't and they're trying to use async
      // act, then they need to upgrade from 16.8 to 16.9.
      // This is a seemless upgrade, so we'll add a warning
      console.error(
        `It looks like you're using a version of react-dom that supports the "act" function, but not an awaitable version of "act" which you will need. Please upgrade to at least react-dom@16.9.0 to remove this warning.`,
      )
      youHaveBeenWarned = true
    }
    await cb()
    // make all effects resolve after
    act(() => {})
  }