public async Task TestUserByPK()
{
var userId = users.FirstOrDefault().Id.ToString();
urlfmt.Values = userId;
var url = urlfmt.Url;
var user = await ahttp.GetByPk(url);
Console.WriteLine($"Test User by primary key:");
Console.WriteLine($" - Primary key: {urlfmt.Values} {(user != null ? "found" : "not found")}");
}