return HttpPostedFile in service with async Task
<p>I have async Task method like these:</p>

<pre><code> public async Task&lt;Slider&gt; EditSlider(HttpPostedFileBase file)
    {

            if (file != null)
            {
                var pic = Path.GetFileName(file.FileName);
                var path = Path.Combine(HttpContext.Current.Server.MapPath("~/Content/images/slider"), pic);
                file.SaveAs(path);
            }
            return file;
    }
</code></pre>

<p>but in <code>return file</code> line I get </p>

<blockquote>
  <p>Cannot convert expression HttpPostedFileBase to async method return type</p>
</blockquote>

<p>How can I return it?
Thanks in advance!</p>