Sometimes improvements are added that very likely benefit all users. These improvements are usually not enabled because of backward compatibility.

If a new user starts using a newer version, it is cumbersome to enable all those improvements explicitly. It would help users if they can indicate which version they want the default settings of. For example:

// Uses the defaults of the oldest version. Ensures all
// existing clients continue to work as they do now.
ArgumentParsers.newFor("app")

// Uses the defaults chosen for version 1.2. Will continue
// to work as desired when upgrading to newer releases.
ArgumentParsers.newFor("app", VERSION_1_2_DEFAULT_SETTINGS)