def METHOD_NAME(self, aws_obj, instances_in_az):
    """
    1. get vpc_id
    2. create security group in this vpc
    3. block availability zone by using "append_security_group"
    Args:
        aws_obj (obj): aws.AWS() object
        instances_in_az (list): ec2_instances within selected availability zone
    Returns:
        security_group_id (str): Newly created security id without access permissions
    """
    group_name = "TEST_SEC_GROUP"
    dict_permissions = {
        "IpProtocol": "tcp",
        "FromPort": 80,
        "ToPort": 80,
        "IpRanges": [{"CidrIp": "1.1.1.1/32"}],
    }
    vpc_id = aws_obj.get_vpc_id_by_instance_id(instances_in_az[0])
    security_group_id = aws_obj.create_security_group(
        group_name, dict_permissions, vpc_id
    )
    aws_obj.block_instances_access(security_group_id, instances_in_az)
    return security_group_id