def __init__(self, groups=None):
        super(GroupedRequirements, self).__init__(NamedRequirements)
        self.groups = groups or self.default_groups
        self.filename = None
        self.create_default_groups()
def add_arguments(self, parser):
        parser.add_argument('--noinput', action='store_false',
                            dest='interactive', default=True,
                            help='Do not prompt for input of any kind.')
        parser.add_argument('-l', '--list', action='store_true',
                            dest='list', default=False,
                            help="Just list the requirements, don't install them.")