Do we still need Display? Confused why we need serde and display on these enums, which one does the metrics library use?

Im pretty sure the Display macro still needs to be there if we want the auto to_string implemented without having to manually implement fmt::Display for Enum

Then what is serde used for?

serde is For Serializing and Deserializing back and for from rust data types to usable structures like json and yaml. But from what I understand if you want to_string you need to implement Display. The reason we need both here is because the container attribute need to access the Deserializer from the derive. Well at least thats what I think but when I remove it, it gives an error

I think you should be able to remove both Deserialize and #[serde(...)], I don't see that being used anywhere. Display is being used for to_string() and you can add back that #[display(style = "lowercase")] if you want to lowercase (maybe use snake case?) the enums

Yeh that its true, I have just changed