public async Task ListAllCustomersTest()
{
var databaseRepoMock = new Mock <IDatabaseRepository>();
databaseRepoMock.Setup(repo => repo.ReadDatabase().Result).Returns(TestDatabaseFilled);
var customerDataService = new CustomerDataService(databaseRepoMock.Object, _mockLogger.Object);
var customers = await customerDataService.ListAllCustomers();
Assert.NotEmpty(customers);
}