00Overview
The `transfer()` function uses an unchecked subtraction. Sending more tokens than the balance causes an integer underflow, wrapping the balance to `2^256 - 1`.
01Trigger underflow
Transfer an amount exceeding balance to any address.
javascript
await contract.transfer("0xdeadbeef...", 21)
// balance was 20; 20 - 21 underflows to 2^256 - 102Level Completed
