public async void EvaluateFunction(string functionName, string param1 = null,
                                           string param2 = null, string param3 = null, string param4 = null
                                           )
        {
            var result = await Run(() => Itr.EvaluateFunction(functionName, param1, param2, param3, param4));

            LogProgress(string.Format("'{0}()' returns: '{1}'", functionName, result));
        }