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 __getitem__(self, key):
        logger.debug("Get /%s config key", "/".join(self._path + (key,)))
        value = self._collection[key]
        return self._to_python(value)