if err != nil {
		return nil, err
	}

	for _, fn := range fns {
		fn(config)
	}

	return config, nil
}

// adjustCommand returns the last component of the
// OS-specific command path for use in User-Agent.
func adjustCommand(p string) string {
	// Unlikely, but better than returning "".
	if len(p) == 0 {
		return "unknown"
	}
	return filepath.Base(p)
}