pyth-network_pyth-crosschain/ethereum/contracts/pyth/PythImplementation.sol

// contracts/Implementation.sol
// SPDX-License-Identifier: Apache 2

pragma solidity ^0.8.0;
pragma experimental ABIEncoderV2;

import "@openzeppelin/contracts/proxy/ERC1967/ERC1967Upgrade.sol";

import "./Pyth.sol";


contract PythImplementation is Pyth {
    modifier initializer() {
        address impl = ERC1967Upgrade._getImplementation();

        require(
            !isInitialized(impl),
            "already initialized"
        );

        setInitialized(impl);

        _;
    }
}