Argument<string> methodsArgument = new(@"method(s)", () => CryptoList.All, @"Methods separated by commas.");
Option<double> secondsOption = new(@"--seconds", () => 3.0, @"Run benchmarks for num seconds.");

Argument<string> methodsArgument = new(@"method(s)")
{
    Description = @"Methods separated by commas.",
    DefaultValueFactory = _ => CryptoList.All
};
Option<double> secondsOption = new(@"--seconds", [@"-s"])
{
    Description = @"Run benchmarks for num seconds.",
    DefaultValueFactory = _ => 3.0
};

methodsArgument.AddCompletions(CryptoList.All);
methodsArgument.AddCompletions(method);

methodsArgument.CompletionSources.Add(new[] { CryptoList.All });
methodsArgument.CompletionSources.Add(CryptoList.Methods.ToArray());

RootCommand cmd = [methodsArgument, secondsOption, bytesOption];

RootCommand cmd = new(@"CryptoBase Speed Test");
cmd.Add(methodsArgument);
cmd.Add(secondsOption);
cmd.Add(bytesOption);

cmd.SetHandler((methods, seconds, bytes) => { /* ... */ }, methodsArgument, secondsOption, bytesOption);
return cmd.Invoke(args);

cmd.SetAction((parseResult) =>
{
    string methods = parseResult.GetValue(methodsArgument)!;
    double seconds = parseResult.GetValue(secondsOption);
    int bytes = parseResult.GetValue(bytesOption);
    /* ... */
});
return cmd.Parse(args).Invoke();