private bool Engage(string distinctId, IDictionary<string, object> setProperties = null,
IDictionary<string, object> incrementProperties = null) {
// Standardize token and time values for Mixpanel
var dictionary =
new Dictionary<string, object> {{"$token", token}, {"$distinct_id", distinctId}};
if (setProperties != null) dictionary.Add("$set", setProperties);
if (incrementProperties != null) dictionary.Add("$add", incrementProperties);
var data = new JavaScriptSerializer().Serialize(dictionary);
var values = "data=" + data.Base64Encode();
var contents = _options.UseGet
? http.Get(Resources.Engage(_options.ProxyUrl), values)
: http.Post(Resources.Engage(_options.ProxyUrl), values);
return contents == "1";
}