detect an EventCallback #528

<EditForm Model="Variable" OnValidSubmit="OnValidSubmit">
</EditForm>

[Parameter]
public Variable Variable { get; set; } = new();
[Parameter]
public EventCallback Updated { get; set; }

protected async Task OnValidSubmit(EditContext context)
{
    try
    {
        //code
        await Updated.InvokeAsync();
    }
    catch (Exception ex)
    {
        ex.ProcessError(Toaster, Logger, context.Model);
    }
}

Action UpdatedHandler = () => { };

var model = FakeData.GetVariable().Generate();

var cut = ctx.RenderComponent<VariableData>(parameters => parameters
    .Add(p => p.Updated, UpdatedHandler)
    .Add(p => p.Variable, model)
);

cut.FindByTag("form").Submit();

Assert.AreEqual(true, cut.Instance.Updated.HasDelegate);