public void OnWritingSystemIDChange_DifferentId_OldIdIsRemoved() { var ws = new WritingSystemDefinition("fr"); RepositoryUnderTest.Set(ws); Assert.IsTrue(RepositoryUnderTest.Contains("fr")); ws.Language = "th"; RepositoryUnderTest.OnWritingSystemIDChange(ws, "fr"); Assert.IsFalse(RepositoryUnderTest.Contains("fr")); Assert.IsTrue(RepositoryUnderTest.Contains("th")); }