PlatformExtensionsInvokeNullableAsyncT - метод

public static Task InvokeNullableAsync<T>(
	this EventHandler<T> eventHandler,
	Object sender,
	T eventArgs,
	CancellationToken cancellationToken = default
)
where T : DeferredEventArgs

<ExtensionAttribute>
Public Shared Function InvokeNullableAsync(Of T As DeferredEventArgs) ( 
	eventHandler As EventHandler(Of T),
	sender As Object,
	eventArgs As T,
	Optional cancellationToken As CancellationToken = Nothing
) As Task

public:
[ExtensionAttribute]
generic<typename T>
where T : DeferredEventArgs
static Task^ InvokeNullableAsync(
	EventHandler<T>^ eventHandler, 
	Object^ sender, 
	T eventArgs, 
	CancellationToken cancellationToken = CancellationToken()
)

[<ExtensionAttribute>]
static member InvokeNullableAsync : 
        eventHandler : EventHandler<'T> * 
        sender : Object * 
        eventArgs : 'T * 
        ?cancellationToken : CancellationToken 
(* Defaults:
        let _cancellationToken = defaultArg cancellationToken new CancellationToken()
*)
-> Task  when 'T : DeferredEventArgs