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 * **[on some of my favorite openzeppelin smart contracts](https://mirror.xyz/go-outside.eth/7Q5DK8cZNZ5CP6ThJjEithPvjgckA24D2wb-j0Ps5-I)**
 * **[reusable properties for ethereum contracts, by trailofbits](https://blog.trailofbits.com/2023/02/27/reusable-properties-ethereum-contracts-echidna/)**
+
+###### solidity useful
+
+* **[permit2 (more robust token approval)](https://github.com/Uniswap/permit2)**