https://mongodb.github.io/mongo-csharp-driver/3.4.0/api/MongoDB.Bson/MongoDB.Bson.Serialization.IdGenerators.BsonBinaryDataGuidGenerator.-ctor.html
Constructor BsonBinaryDataGuidGenerator | MongoDB CSharp Driver API Reference
constructormongodbcsharpdriverapi
https://mongodb.github.io/mongo-csharp-driver/2.17/apidocs/html/M_MongoDB_Bson_Serialization_IdGenerators_BsonBinaryDataGuidGenerator_IsEmpty.htm
BsonBinaryDataGuidGenerator.IsEmpty Method
Tests whether an Id is empty.
isemptymethod