def list_vms():
    salt.utils.warn_until('Nitrogen', 'Use "virt.list_domains" instead.')
    return list_domains()
add another list-like object
dataset/ETHPy150Open saltstack/salt/salt/modules/virt.py/list_vms--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.5/django/contrib/gis/geos/mutable_list.py/ListMixin.__add__