private Optional<BlockHeader> getBlockHeader(
      final Hash blockHash, final Supplier<Boolean> isQueryAlive) throws Exception {
    return BackendQuery.runIfAlive(
        "matchingLogs - getBlockHeader", () -> blockchain.getBlockHeader(blockHash), isQueryAlive);
  }
Calculate and return the value of the base fee for the next block, if the network has a base
fee market, otherwise return empty.

@return the optional base fee
ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/query/BlockchainQueries.java