'Run after every live migration operation.
:param device_info_dict: : the data dict
:param extra_specs: extra specifications'

def post_live_migration(self, device_info_dict, extra_specs):

    array = device_info_dict['array']
    source_sg = device_info_dict['source_sg']
    num_vol_in_sg = self.rest.get_num_vols_in_sg(array, source_sg)
    if (num_vol_in_sg == 0):
        self.rest.remove_child_sg_from_parent_sg(array, source_sg, device_info_dict['source_parent_sg'], extra_specs)
        self.rest.delete_storage_group(array, source_sg)
