Implement a Key-Value Store With Transactions (Go)

Problem

Implement an in-memory key-value store with set, get, delete, and begin/commit/rollback (a reported HashiCorp 'db transaction scenario' in Go).

Example

begin(); set(a,1); rollback(); get(a) -> nil

Constraints

• Nested transactions roll back correctly

What HashiCorp looks for

HashiCorp avoids LeetCode puzzles — this is practical machine coding. Clean Go, clear naming, and tests matter.