private SECPSignature createCommitSeal(final Block block) {
    final BlockHeader proposedHeader = block.getHeader();
    final BftExtraData extraData = bftExtraDataCodec.decode(proposedHeader);
    final Hash commitHash =
        new BftBlockHashing(bftExtraDataCodec)
            .calculateDataHashForCommittedSeal(proposedHeader, extraData);
    return nodeKey.sign(commitHash);
  }
Construct prepared round artifacts.

@return the optional prepared round artifacts
consensus/ibft/src/main/java/org/hyperledger/besu/consensus/ibft/statemachine/IbftRound.java