public static string PostToUrl(this string url, object formData = null, string acceptContentType = "*/*",
Action<HttpWebRequest> requestFilter = null, Action<HttpWebResponse> responseFilter = null)
{
string postFormData = formData != null ? QueryStringSerializer.SerializeToString(formData) : null;
return SendStringToUrl(url, method: "POST",
contentType: FormUrlEncoded, requestBody: postFormData,
acceptContentType: acceptContentType, requestFilter: requestFilter, responseFilter: responseFilter);
}