These methods would allow the decision whether a particular property should be serialized to be made at runtime. This is similar to [BsonIgnoreIfNull] but allows the developer to use custom criteria to decide whether to serialize the property or not. For example:

public class Employee {
// other fields
public string Zip;

public bool ShouldSerializeZip(string value)

{ return value != null && value != "' && value != "00000"; }

}