https://github.com/code-423n4/2023-09-asymmetry/blob/main/contracts/AfEth.sol#L183
When a user requests a withdrawal in AfEth, their tokens are transferred to the contract and locked until the withdrawal is made effective, at which point the tokens are burned.
Given this mechanism, AfEth tokens held by the same contract are considered as locked tokens but anyone can technically transfer tokens to the contract by calling transfer() or transferFrom().
Consider adding a check to the base ERC20 functionality to prevent AfEth tokens from being sent to the contract by external actors.
