https://mongodb.github.io/mongo-csharp-driver/2.12/apidocs/html/M_MongoDB_Bson_Serialization_IBsonSerializerExtensions_ToBsonValue__1.htm
IBsonSerializerExtensions.ToBsonValue(TValue) Method (IBsonSerializer(TValue), TValue)
Converts a value to a BsonValue by serializing it.
method
https://mongodb.github.io/mongo-csharp-driver/3.0.0/api/MongoDB.Driver/MongoDB.Driver.WriteConcern.WMode.ToBsonValue.html
Method ToBsonValue | MongoDB CSharp Driver API Reference
methodmongodbcsharpdriverapi