ERC1822: Universal Upgradeable Proxy Standard (UUPS) documents a method for upgradeability through a simplified proxy whose upgrades are fully controlled by the current implementation.
function proxiableUUID() external view returns (bytes32)
Returns the storage slot that the proxiable contract assumes is being used to store the implementation address. IMPORTANT: A proxy pointing at a proxiable contract should not be considered proxiable itself, because this risks bricking a proxy that upgrades to it, by delegating to itself until out of gas. Thus it is critical that this function revert if invoked through a proxy.