File: PriceOracle.sol

function getAssetPriceFromChainlink(address asset) public view returns (uint256) {
   AggregatorV2V3Interface sourceAgg = assetChainlinkAggregators[asset];
   require(address(sourceAgg) != address(0), Errors.ASSET_AGGREGATOR_NOT_EXIST);
   if (!isSequencerActive()) revert Errors.L2SequencerUnavailable();

    ...
}

function isSequencerActive() internal view returns (bool) {
    (, int256 answer, uint256 startedAt,,) = sequencer.latestRoundData();
    if (block.timestamp - startedAt <= GRACE_PERIOD_TIME || answer == 1)
        return false;
    return true;
}
