importFiles = (ipfs, files) => {
  /** @type {Channel<{ offset:number, name: string}>} */
  const channel = new Channel()
  const result = all(ipfs.addAll(files, {
    pin: false,
    wrapWithDirectory: false,
    progress: (offset, name) => channel.send({ offset, name })
  }))

  result.then(() => channel.close(), error => channel.close(error))

  return { result, progress: channel }
}
@param {IPFSService} ipfs
@param {FileStream[]} files