moto/tests/test_cloudformation/fixtures/fn_join.py

template = {
    "Resources": {"EC2EIP": {"Type": "AWS::EC2::EIP"}},
    "Outputs": {
        "EIP": {
            "Description": "EIP for joining",
            "Value": {"Fn::Join": [":", ["test eip", {"Ref": "EC2EIP"}]]},
        }
    },
}