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 delete_snapshot_metadata_item(self, snapshot_id, id):
        """Delete metadata item for the snapshot."""
        url = "snapshots/%s/metadata/%s" % (str(snapshot_id), str(id))
        resp, body = self.delete(url)
        return resp, body