uma/packages/core/contracts/common/implementation/MultiCaller.sol

// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity ^0.8.0;

// This contract is taken from Uniswap's multi call implementation (https://github.com/Uniswap/uniswap-v3-periphery/blob/main/contracts/base/Multicall.sol)
// and was modified to be solidity 0.8 compatible. Additionally, the method was restricted to only work with msg.value
// set to 0 to avoid any nasty attack vectors on function calls that use value sent with deposits.

/// @title MultiCaller
/// @notice Enables calling multiple methods in a single call to the contract
contract MultiCaller {
    function multicall(bytes[] calldata data) external returns (bytes[] memory results) {
        results = new bytes[](data.length);
        for (uint256 i = 0; i < data.length; i++) {
            (bool success, bytes memory result) = address(this).delegatecall(data[i]);

            if (!success) {
                // Next 5 lines from https://ethereum.stackexchange.com/a/83577
                if (result.length < 68) revert();
                assembly {
                    result := add(result, 0x04)
                }
                revert(abi.decode(result, (string)));
            }

            results[i] = result;
        }
    }
}