'Creates a new subcommand. name is the primary way to invoke
the subcommand; aliases are alternate names. parser is an
OptionParser responsible for parsing the subcommand\'s options.
help is a short description of the command. If no parser is
given, it defaults to a new, empty CommonOptionsParser.'

def __init__(self, name, parser=None, help='', aliases=(), hide=False):

    self.name = name
    self.parser = (parser or CommonOptionsParser())
    self.aliases = aliases
    self.help = help
    self.hide = hide
    self._root_parser = None
