public async Task Test_CreateAsync_Concrete_Async()
{
// Cancellation token.
CancellationToken cancellationToken = CancellationToken.None;
// The client factory.
var factory = new HttpClientFactory();
// Not null.
Assert.NotNull(factory);
// Create client.
HttpClient client = await factory.CreateAsync(null, true, cancellationToken).ConfigureAwait(false);
// Not null.
Assert.NotNull(client);
}