Task<ReplaceOneResult> ReplaceOneAsync(
	FilterDefinition<TDocument> filter,
	TDocument replacement,
	UpdateOptions options = null,
	CancellationToken cancellationToken = null
)

Function ReplaceOneAsync ( 
	filter As FilterDefinition(Of TDocument),
	replacement As TDocument,
	Optional options As UpdateOptions = Nothing,
	Optional cancellationToken As CancellationToken = Nothing
) As Task(Of ReplaceOneResult)

abstract ReplaceOneAsync : 
        filter : FilterDefinition<'TDocument> * 
        replacement : 'TDocument * 
        ?options : UpdateOptions * 
        ?cancellationToken : CancellationToken 
(* Defaults:
        let _options = defaultArg options null
        let _cancellationToken = defaultArg cancellationToken null
*)
-> Task<ReplaceOneResult>