@classmethod
def get_available_commands(cls):
    """
        Get a list of commands that we can execute.  By default, we have a
        fixed list that we make available in this directory, but the user can
        create her own plugins and store them at
        ~/.config/ripe-atlas-tools/commands/.  If we find any files there, we
        add them to the list here.
        """
    if not cls._commands:
        cls._load_commands()
    return sorted(cls._commands.keys())
