public void Clone_AddAttribute_NotEquals(Fb2Node instance) { if (instance.AllowedAttributes == null || !instance.AllowedAttributes.Any()) { return; } var instanceTwo = instance.Clone() as Fb2Node; instanceTwo.AddAttribute(new Fb2Attribute(instance.AllowedAttributes.First(), "testValue")); instance.Should().NotBe(instanceTwo); instance.Attributes.Should().BeEmpty(); instanceTwo.Attributes.Should().NotBeEmpty().And.HaveCount(1); }