public void ClearCustomers_Test()
        {
            // Arrange
            var viewModel = new CustomerViewModel();

            // Act
            viewModel.ClearCustomers();

            // Assert
            Assert.IsNotNull(viewModel.Customers);
            Assert.AreEqual(0, viewModel.Customers.Count());
        }
 private void ClearDataButton_Click(object sender, RoutedEventArgs e)
 {
     viewModel.ClearCustomers();
 }