/// <summary/>
public void UpdateWritingSystemListField_RemovesWsCode()
{
int m_wsEn = Cache.WritingSystemFactory.GetWsFromStr("en");
int m_wsFr = Cache.WritingSystemFactory.GetWsFromStr("fr");
CoreWritingSystemDefinition enBlz;
WritingSystemServices.FindOrCreateWritingSystem(Cache, null, "blz", false, false, out enBlz);
var revIndex = Cache.ServiceLocator.GetInstance <IReversalIndexRepository>().FindOrCreateIndexForWs(m_wsEn);
var entry1 = SenseOrEntryTests.CreateInterestingLexEntry(Cache);
var msa1 = Cache.ServiceLocator.GetInstance <IMoStemMsaFactory>().Create();
entry1.MorphoSyntaxAnalysesOC.Add(msa1);
entry1.SensesOS.First().MorphoSyntaxAnalysisRA = msa1;
var entry2 = SenseOrEntryTests.CreateInterestingLexEntry(Cache);
var msa2 = Cache.ServiceLocator.GetInstance <IMoStemMsaFactory>().Create();
entry2.MorphoSyntaxAnalysesOC.Add(msa2);
entry2.SensesOS.First().MorphoSyntaxAnalysisRA = msa2;
var testEntry = revIndex.FindOrCreateReversalEntry("first");
testEntry.SensesRS.Add(entry1.SensesOS.First());
testEntry.SensesRS.Add(entry2.SensesOS.First());
testEntry.ReversalIndex.WritingSystem = "fr";
testEntry.ReversalForm.set_String(m_wsFr, "fr");
WritingSystemServices.UpdateWritingSystemFields(Cache, "fr", "blz");
Assert.DoesNotThrow(() => WritingSystemServices.UpdateWritingSystemFields(Cache, "fr", null));
Assert.That(testEntry.ReversalIndex.WritingSystem, Is.EqualTo("blz"));
Assert.That(testEntry.ReversalIndex.ShortName, Is.EqualTo("Balantak"));
}