protected const int BufferSize = 1 << 20; // 1MB
public virtual async Task DownloadFile(string downloadUrl, FsPath downloadTarget, CancellationToken token)
{
using var stream = await DownloadStream(downloadUrl, token);
using var fileStream = downloadTarget.OpenFile(FileMode.Create);
await stream.CopyToAsync(fileStream, BufferSize, token);
}