public WriteConcern(
	string mode,
	Optional<Nullable<TimeSpan>> wTimeout = null,
	Optional<Nullable<bool>> fsync = null,
	Optional<Nullable<bool>> journal = null
)

Public Sub New ( 
	mode As String,
	Optional wTimeout As Optional(Of Nullable(Of TimeSpan)) = Nothing,
	Optional fsync As Optional(Of Nullable(Of Boolean)) = Nothing,
	Optional journal As Optional(Of Nullable(Of Boolean)) = Nothing
)

new : 
        mode : string * 
        ?wTimeout : Optional<Nullable<TimeSpan>> * 
        ?fsync : Optional<Nullable<bool>> * 
        ?journal : Optional<Nullable<bool>> 
(* Defaults:
        let _wTimeout = defaultArg wTimeout null
        let _fsync = defaultArg fsync null
        let _journal = defaultArg journal null
*)
-> WriteConcern