code: def revert(self, snapshot: Tuple[Hash32, UUID]) -> None:
          
          state_root, account_snapshot = snapshot
  
          # first revert the database state root.
          self._account_db.state_root = state_root
          # now roll the underlying database back
          self._account_db.discard(account_snapshot)
docs: Revert the VM to the state at the snapshot