'Create a security group without rules.
Default rules will be created:
- IPv4 egress to any
- IPv6 egress to any
:param tenant_id: secgroup will be created in this tenant
:returns: the created security group'

def _create_empty_security_group(self, client=None, tenant_id=None, namestart='secgroup-smoke'):

    if (client is None):
        client = self.security_groups_client
    if (not tenant_id):
        tenant_id = client.tenant_id
    sg_name = data_utils.rand_name(namestart)
    sg_desc = (sg_name + '    description')
    sg_dict = dict(name=sg_name, description=sg_desc)
    sg_dict['tenant_id'] = tenant_id
    result = client.create_security_group(**sg_dict)
    secgroup = result['security_group']
    self.assertEqual(secgroup['name'], sg_name)
    self.assertEqual(tenant_id, secgroup['tenant_id'])
    self.assertEqual(secgroup['description'], sg_desc)
    self.addCleanup(test_utils.call_and_ignore_notfound_exc, client.delete_security_group, secgroup['id'])
    return secgroup
