[Fact]
public void CustomerServiceShouldAddCustomerAndReturnId()
{
    //Arrange
    var fixture = new Fixture();
    fixture.Customize<Customer>(e => e.With(x=>x.Phone,GeneratePhone());

    var @object = fixture.Build<Customer>()
        .Without(s=>s.Id)
        .Create();
    //Act
    var sut = _customerServices.Add(@object);

    //Assert
    sut.Should().GreaterThan(0);
}