Hvordan indstilles MongoDB Change Stream 'OperationType' i C#-driveren?

Her er et eksempel på kode, jeg har brugt til at opdatere samlingen Watch for at hente andre "begivenheder" end blot dokumentopdateringer.

IMongoDatabase sandboxDB = mongoClient.GetDatabase("Sandbox");
IMongoCollection<BsonDocument> collection = sandboxDB.GetCollection<BsonDocument>("TestCollection");

//Get the whole document instead of just the changed portion
ChangeStreamOptions options = new ChangeStreamOptions() { FullDocument = ChangeStreamFullDocumentOption.UpdateLookup };

//The operationType can be one of the following: insert, update, replace, delete, invalidate
var pipeline = new EmptyPipelineDefinition<ChangeStreamDocument<BsonDocument>>().Match("{ operationType: { $in: [ 'replace', 'insert', 'update' ] } }");

var changeStream = collection.Watch(pipeline, options).ToEnumerable().GetEnumerator();
changeStream.MoveNext();    //Blocks until a document is replaced, inserted or updated in the TestCollection
ChangeStreamDocument<BsonDocument> next = changeStream.Current;
enumerator.Dispose();

EmptyPiplineDefinition...Match()-argumentet kunne også være:

"{ $or: [ {operationType: 'replace' }, { operationType: 'insert' }, { operationType: 'update' } ] }"

Hvis du ville bruge kommandoen $or, eller

"{ operationType: /^[^d]/  }"

at smide lidt regex derind. Denne sidste siger, jeg vil have alle operationstyper, medmindre de starter med bogstavet 'd'.