private void tryParseError_JSON(string source)
        {
            //using (var reader = new JsonTextReader(new StringReader(source)))
            //{
            //	// TODO:

            //}
            // if someone will caught exception
            IsError = true;
            Error = new VKErrorResponse()
            {
                Code = -1,
                Message = INTERNAL_NOT_IMPLEMENTED_ERROR,
                RequestParams = new KeyValuePair<string,string>[0]
            };

            throw new NotImplementedException();
        }
        private void tryParseError_XML(string source)
        {
            var doc = XDocument.Parse(source);

            if (doc.Root.Name == RESPONSE_NODE_NAME_ERROR)
            {
                Error = new VKErrorResponse()
                {
                    Code = Int32.Parse(doc.Root.Element(RESPONSE_NODE_NAME_ERROR_CODE).Value),
                    Message = doc.Root.Element(RESPONSE_NODE_NAME_ERROR_MSG).Value,
                    RequestParams = (
                                    from node
                                    in doc.Root.Elements(RESPONSE_NODE_NAME_REQUEST_PARAMS).Elements(RESPONSE_NODE_NAME_PARAM)
                                    select new KeyValuePair<string, string>(
                                        node.Element("key").Value,
                                        node.Element("value").Value
                                        )
                                    ).ToArray()
                };
                IsError = true;
            }
            else
            {
                Error = new VKErrorResponse()
                {
                    Code = 0,
                    Message = String.Empty,
                    RequestParams = new KeyValuePair<string, string>[0]
                };
                IsError = false;
            }
        }