SushiToken (xSushi)
The SushiToken contract implements all the ERC20 token functions. Governance is also baked into the token. Though there is a known vulnerability related to vote delegation, and it is advised not to use the governance in production / on-chain.
The full contract can be found here.
State-Changing Functions
Uses all of your usual openzeppelin ERC20 functionality through inheritance from the ERC20 standard.