FileExtensionsOpenAsync - метод

<ExtensionAttribute>
Public Shared Function OpenAsync ( 
	obj As IFileObject,
	Optional openingMode As FileOpeningMode = FileOpeningMode.ForRead,
	Optional getContentFuncAsync As Func(Of IFileObject, CancellationToken, ValueTask(Of IFileContent)) = Nothing,
	Optional cancellationToken As CancellationToken = Nothing
) As ValueTask(Of ValidationResult)

public:
[ExtensionAttribute]
static ValueTask<ValidationResult^> OpenAsync(
	IFileObject^ obj, 
	FileOpeningMode openingMode = FileOpeningMode::ForRead, 
	Func<IFileObject^, CancellationToken, ValueTask<IFileContent^>>^ getContentFuncAsync = nullptr, 
	CancellationToken cancellationToken = CancellationToken()
)

[<ExtensionAttribute>]
static member OpenAsync : 
        obj : IFileObject * 
        ?openingMode : FileOpeningMode * 
        ?getContentFuncAsync : Func<IFileObject, CancellationToken, ValueTask<IFileContent>> * 
        ?cancellationToken : CancellationToken 
(* Defaults:
        let _openingMode = defaultArg openingMode FileOpeningMode.ForRead
        let _getContentFuncAsync = defaultArg getContentFuncAsync null
        let _cancellationToken = defaultArg cancellationToken new CancellationToken()
*)
-> ValueTask<ValidationResult>