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 _load_data(self, directory):
        try:
            with open(directory, 'r') as f:
                data = f.read()
                return literal_eval(data)
        except OSError as e:
            raise