Where is HelpOptionAttribute?

I saw some samples that look like this:

[HelpOption]
public string GetUsage()
{
  var help = new HelpText {
    Heading = new HeadingInfo("<<app title>>", "<<app version>>"),
    Copyright = new CopyrightInfo("<<app author>>", 2014),
    AdditionalNewLineAfterOption = true,
    AddDashesToOption = true
  };
  help.AddPreOptionsLine("<<license details here.>>");
  help.AddPreOptionsLine("Usage: app -p Someone");
  help.AddOptions(this);
  return help;
}

However it doesn’t seem like HelpOptionAttribute exists in the latest release (2.1.1-beta). What do I use instead?

[theOrillian]

Is it possible to derive the usage text without being in the middle of a parse operation? All I want is a method Options.GetUsage() that spits out the usage info as it would as if --help was one of the arguments.

[dev-thinks]

Hmmm…downgrading to old version. Thanks.