private async void AddDoctorBtn_Click(object sender, RoutedEventArgs e)
        {
            try
            {
                AddMedicineBtn.IsEnabled = false;
                string  name = NameTextBox.Text;
                string  sku  = SkuTextBox.Text;
                decimal price;
                string  indication = IndicationTextBox.Text;
                string  country    = CountryTextBox.Text;

                if (string.IsNullOrWhiteSpace(name))
                {
                    throw new ArgumentNullException($"'{nameof(name)}' is incorrect");
                }
                if (string.IsNullOrWhiteSpace(sku))
                {
                    throw new ArgumentNullException($"'{nameof(sku)}' is incorrect");
                }
                if (string.IsNullOrWhiteSpace(indication))
                {
                    throw new ArgumentNullException($"'{nameof(indication)}' is incorrect");
                }
                if (string.IsNullOrWhiteSpace(country))
                {
                    throw new ArgumentNullException($"'{nameof(country)}' is incorrect");
                }
                if (!decimal.TryParse(PriceTextBox.Text, out price))
                {
                    throw new ArgumentNullException($"'{nameof(price)}' is incorrect");
                }
                if (price < 0)
                {
                    throw new ArgumentNullException($"'{nameof(price)}' is incorrect");
                }

                Medicine requestMedicine = new Medicine
                {
                    Name       = name,
                    Price      = price,
                    Sku        = sku,
                    Indication = indication,
                    Country    = new Country
                    {
                        Name = country
                    }
                };

                string request = tcpService.SerializeAddMedicineRequest(requestMedicine, SingletoneObj.User);
                byte[] data    = await tcpService.CodeStreamAsync(request);

                await SingletoneObj.Stream.WriteAsync(data, 0, data.Length);

                string response = await tcpService.DecodeStreamAsync(SingletoneObj.Stream);

                var responseArgs = response.Split(';');
                if (responseArgs.Length > 1 && responseArgs[0].Contains("500"))
                {
                    throw new ArgumentException(responseArgs[1]);
                }
                this.Close();
            }
            catch (Exception ex)
            {
                AddMedicineBtn.IsEnabled = true;
                StatusLabel.Content      = "Status: " + ex.Message;
            }
        }