'Creates a group_snapshot.
:param context: the context of the caller.
:param group_snapshot: the GroupSnapshot object to be created.
:param snapshots: a list of Snapshot objects in the group_snapshot.
:returns: model_update, snapshots_model_update'

def create_group_snapshot(self, context, group_snapshot, snapshots):

    return self.create_cgsnapshot(context, group_snapshot, snapshots)
