private void peerIsPrepared(final Prepare msg) {
    final boolean wasPrepared = roundState.isPrepared();
    roundState.addPrepareMessage(msg);
    if (wasPrepared != roundState.isPrepared()) {
      LOG.debug("Sending commit message. round={}", roundState.getRoundIdentifier());
      final Block block = roundState.getProposedBlock().get();
      try {
        transmitter.multicastCommit(getRoundIdentifier(), block.getHash(), createCommitSeal(block));
        // Note: the local-node's commit message was added to RoundState on block acceptance
        // and thus does not need to be done again here.
      } catch (final SecurityModuleException e) {
        LOG.warn("Failed to construct a commit seal: {}", e.getMessage());
      }
    }
  }
Construct prepared round artifacts.

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