How about uint256 as well?

Could rename this to testInsertAndGet since testGet 100% reproduces testInsert. I understand why you didn't do this conceptually, but it's hard to imagine how testGet will evolve in a way that deviates substantially without testing inserts as a consequence.

uint256 here too

remove duplicate comment

Using a discriminant to discriminate a discriminated union seems appropriate.

Please pay attention.

dito

initialization

You'll get failure and you don't know if insert of get failed.

in chunk -> into chunks
as index -> as an index

lazyly -> lazily
leaf -> leafs

element -> elements

require to wait -> requires waiting

beofre -> before

is -> if

match -> matches

untill -> until

already was -> was already

inertion in -> insertion into

work -> works (I think)

in -> into

"They can a be inserted"
Unsure what you are trying to say, the "a" seems superfluous.

in -> into

element -> elements

in -> into

others -> other

element -> elements
in -> into

I think it is leaves :)

Yeah, maybe "leaves" is better, but I think you could write either and still be considered correct.

For example, in electrical engineering "antennas" is the standard plural, not "antennae".

see also the "Toronto Maple Leafs"

We're getting into the arcana of linguistics, but in English is is considered normal to "standardize" grammar rules for a word when it occupies a new cognitive category. That seems to be what people's brains naturally do.

Actually, feel free to ignore my digression.

A quick Google shows that "leaves" is better.

ya, I'm just saying the function name makes no sense

We get it for free when calling getId :)

It is definitively possible for the caller to cal this when the discriminated union is not a node. It is not the responsibility of the union to decide if we ant null nodes or not.