DelegateTests.cs

[Fact]
public async Task Test()
{
    var sku = Guid.NewGuid().ToString();

    var sut = new GetProductBySkuHandlerDelegateExample(x => Task.FromResult(new Product { Sku = x }));
    var result = await sut.Handle(new GetProductBySkuRequest(sku), CancellationToken.None);

    result.Sku.ShouldBe(sku);
}