HttpWebRequest/DevDefined - Get QBO Employees

//Gets a list of QBO employees using the static base URL and an empty request body (defaults to StartPage=1 and ResultsPerPage=10)

public string GetQboEmployees(string realmId)
{
    HttpWebRequest httpWebRequest = WebRequest.Create("https://qbo.sbfinance.intuit.com/resource/employees/v2/" + realmId) as HttpWebRequest;
    httpWebRequest.Method = "POST";
    httpWebRequest.ContentType = "application/x-www-form-urlencoded";
    httpWebRequest.Headers.Add("Authorization", GetDevDefinedOAuthHeader(httpWebRequest));
    HttpWebResponse httpWebResponse = httpWebRequest.GetResponse() as HttpWebResponse;
    using (Stream data = httpWebResponse.GetResponseStream())
    {
        return new StreamReader(data).ReadToEnd();
    }
}

protected string GetDevDefinedOAuthHeader(HttpWebRequest webRequest)
{

    OAuthConsumerContext consumerContext = new OAuthConsumerContext
    {
        ConsumerKey = consumerKey,
        ConsumerSecret = consumerSecret,
        SignatureMethod = SignatureMethod.HmacSha1

    };

    consumerContext.UseHeaderForOAuthParameters = true;

    OAuthSession oSession = new OAuthSession(consumerContext, "https://www.example.com",
                            "https://www.example.com",
                            "https://www.example.com");


    oSession.AccessToken = new TokenBase
    {
        Token = accessToken,
        ConsumerKey = consumerKey,
        TokenSecret = accessTokenSecret
    };

    IConsumerRequest consumerRequest = oSession.Request();
    consumerRequest = ConsumerRequestExtensions.ForMethod(consumerRequest, webRequest.Method);
    consumerRequest = ConsumerRequestExtensions.ForUri(consumerRequest, webRequest.RequestUri);
    consumerRequest = consumerRequest.SignWithToken();
    return consumerRequest.Context.GenerateOAuthParametersForHeader();
}