An Account That Protects Its Own Rules

Implement Account so that nothing outside the class can break its rules:

• deposit(amount) - amount must be positive, else throw IllegalArgumentException("amount must be positive"). Records deposit <amount> in the history.
• withdraw(amount) - amount must be positive (same error). If the withdrawal would take the balance below -overdraftLimit, throw IllegalStateException("overdraft limit exceeded") and change nothing. Records withdraw <amount>.
• balance() - the current balance.
• history() - the list of recorded operations. Callers must not be able to change the account's history through this list.

The TAMPER command plays a hostile caller that tries to clear the list it gets back and add hacked. If your account is properly encapsulated, the next HISTORY is unaffected.

In Python: raise ValueError("amount must be positive") and RuntimeError("overdraft limit exceeded"). Python has no private: the account's own list is self._history (a leading underscore marks it internal by convention), and history() must not return it.

Commands: NEW <overdraftLimit>, DEPOSIT <n>, WITHDRAW <n>, BALANCE, HISTORY, TAMPER.

Example

Input:
5
NEW 50
DEPOSIT 100
WITHDRAW 140
TAMPER
HISTORY

Output:
overdraft limit 50
balance 100
balance -40
tamper attempted
history [deposit 100, withdraw 140]

• At most 1000 commands; amounts fit in a long.