Unchecked return value for transferFrom calls
There are two `transferFrom` calls that do not check the return value (some tokens signal failure by returning false):\\n```\\nstakedToken.transferFrom(from, address(this), amount);\\n```\\n\\n```\\nfei().transferFrom(msg.sender, address(pair), amountFei);\\n```\\n\\nIt is usually good to add a require-statement that checks the return value or to use something like safeTransferFrom; unless one is sure the given token reverts in case of a failure.
Consider adding a require-statement or using `safeTransferFrom`.
```\\nstakedToken.transferFrom(from, address(this), amount);\\n```\\n