Thank you for bringing this up. You’re correct in observing that the code uses a nested structure of a List of Buckets, where each Bucket is a List of Entries. This is the correct and expected way to implement a hash map in this case.
Regarding the question about three level of nesting, It seems that there may have been a misunderstanding. In the code provided, there is only two levels of nesting, which is the List of Buckets, where each Bucket is a List of Entries.
Can you please clarify where you see the third level of nesting, so that I can help address any confusion or misunderstandings?