'Get a list of groups.
The listing result is an object with property "items".'

@rest_utils.ajax()
def get(self, request):

    domain_context = request.session.get('domain_context')
    items = [d.to_dict() for d in api.keystone.group_list(request, domain=request.GET.get('domain_id', domain_context))]
    return {'items': items}
