title: How to unit test this method in c#?
body: <p>i am learning unit testing. How to unit test this method using nunit and rhino mock ?</p>
  
  <pre><code>public ActionResult PrintCSV(Byte[] bytes, string fileName)
  {
      var file = File(bytes, "application/vnd.ms-excel");
      var cd = new System.Net.Mime.ContentDisposition()
      {
          CreationDate = DateTime.Now,
          FileName = fileName,
          Inline = false
      };
      Response.AppendHeader("Content-Disposition", cd.ToString());
      return file;
  }
  </code></pre>