public void Ids_should_return_set_of_identifiers() { var clocks = new Siblings { { new JObject(new JProperty("v", 1)), DottedVersionVector.Parse("((r,1),{})") }, { new JObject(new JProperty("v", 2)), DottedVersionVector.Parse("((r,2),{})") }, { new JObject(new JProperty("v", 1)), DottedVersionVector.Parse("((s,1),{(t,4)})") }, }; var ids = clocks.Ids(); ids.Should().Contain(new[] { "r", "s", "t" }); ids.Should().HaveCount(3); ids.Should().OnlyHaveUniqueItems(); }