public static Task<Nullable<decimal>> SumAsync(
	this IMongoQueryable<Nullable<decimal>> source,
	CancellationToken cancellationToken = null
)

<ExtensionAttribute>
Public Shared Function SumAsync ( 
	source As IMongoQueryable(Of Nullable(Of Decimal)),
	Optional cancellationToken As CancellationToken = Nothing
) As Task(Of Nullable(Of Decimal))

[<ExtensionAttribute>]
static member SumAsync : 
        source : IMongoQueryable<Nullable<decimal>> * 
        ?cancellationToken : CancellationToken 
(* Defaults:
        let _cancellationToken = defaultArg cancellationToken null
*)
-> Task<Nullable<decimal>>