title: Create FormFile from Stream
body: <p>I want to create a FormFile in my seed function. But I get a null reference exception. Here my code</p>
  
  <pre><code>FileStream fs = new FileStream("testfile.jpg", FileMode.Open, FileAccess.Read);
  FormFile file = new FormFile(fs, 1024, fs.Length, "testfile", "testfile.jpg");
  file.ContentType = "image/jpeg";
  </code></pre>
  
  <p>The null reference occurs when I am trying to set content type. Any Ideas what I am making wrong? Checked before with File.Exists which returns true.</p>