title: RestSharp AddFile adding multipart form headers to file
body: <p>I'm using RestSharp's AddFile and it's working close to fine except my files end up getting broken due to this header information that's being added.</p>
  
  <pre><code>-------------------------------28947758029299
  Content-Disposition: form-data; name="user.png"; filename="user.png"
  Content-Type: image/png
  </code></pre>
  
  <p>This was just a test image I uploaded. If I remove these lines from the file then it opens fine, otherwise it seems to be corrupt.
  Is it possible for me to use AddFile without this stuff getting added?</p>
  
  <p>Current code:</p>
  
  <pre><code>string contentType = MimeMapping.GetMimeMapping("~/uploads/" + filename); //image/png etc
  request.AddFile(filename, Server.MapPath("~") + "\\uploads\\" + filename, contentType);
  IRestResponse response = client.Execute(request);
  </code></pre>
  
  <p>Also tried this with the same result:</p>
  
  <pre><code>request.AddHeader("Content-Type", contentType);
  byte[] bytes = File.ReadAllBytes(Server.MapPath("~") + "\\uploads\\" + filename);
  request.AddBody(new {myFile = File.ReadAllBytes(Server.MapPath("~") + "\\uploads\\" + filename) });
  </code></pre>
  
  <p>Also this (no files went through at all here): <strong>Edit: this worked actually</strong></p>
  
  <pre><code>string contentType = MimeMapping.GetMimeMapping("~/uploads/" + filename);
  byte[] bytes = File.ReadAllBytes(Server.MapPath("~") + "\\uploads\\" + filename);
  
  request.AddHeader("Content-Type", contentType);
  request.AddParameter(contentType, bytes, ParameterType.RequestBody);
  
  IRestResponse response = client.Execute(request);
  </code></pre>