Blend contract
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (interfaces/draft-IERC1822.sol)
pragma solidity ^0.8.0;
 * @dev ERC1822: Universal Upgradeable Proxy Standard (UUPS) documents a method for upgradeability through a simplified
 * proxy whose upgrades are fully controlled by the current implementation.
interface IERC1822ProxiableUpgradeable {
     * @dev 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.
    function proxiableUUID() external view returns (bytes32);