Working examples of the OpenAPI generated clients?

I am using the clients generated from the OpenAPI specification: https://github.com/box/box-openapi

Client code generated for C# targeting .NET framework 3.5; all resultant client libraries build without issue.

I created an app in the dev console and retrieved the auth token.

I am using the following code sample from the generated documentation:

using System;
using System.Diagnostics;
using IC.He.Sdk.Box.Upload.Api;
using IC.He.Sdk.Box.Upload.Client;
using IC.He.Sdk.Box.Upload.Model;

namespace Example
{
    public class UploadFileExample
    {
        public void main()
        {
            // Configure OAuth2 access token for authorization: OAuth2Security
            Configuration.Default.AccessToken = "{MY_ACCESS_TOKEN_HERE}";

            var apiInstance = new FileUploadApi();
            var file = new System.IO.Stream(); // System.IO.Stream | File to upload
            string attributes = "{\"name\": \"10KB.pdf\", \"parent\": { \"id\": \"0\" } }";

            try
            {
                // Upload File
                FileList result = apiInstance.UploadFile(file, attributes);
                Debug.WriteLine(result);
            }
            catch (Exception e)
            {
                Debug.Print("Exception when calling FileUploadApi.UploadFile: " + e.Message );
            }
        }
    }
}

When I make the API call, I see the following outgoing HTTP message:

POST https://upload.box.com/api/2.0/files/content HTTP/1.1
Accept: application/json
Authorization: Bearer {MY_APP_AUTH_TOKEN}
User-Agent: Swagger-Codegen/1.0.0/csharp
Content-Type: multipart/form-data; boundary=-----------------------------2894***phone number removed for privacy***Host: upload.box.com
Content-Length: 206
Accept-Encoding: gzip, deflate
Connection: Keep-Alive

And the following response message:

HTTP/1.1 408 Request body incomplete
Date: Tue, 12 Sep 2017 20:51:31 GMT
Content-Type: text/html; charset=UTF-8
Connection: close
Cache-Control: no-cache, must-revalidate
Timestamp: 16:51:31.782

The request body did not contain the specified number of bytes. Got 155, expected 206 

Not sure if this is user error or an issue with the client generation.

Are there any practical examples of working with the OpenAPI based clients?