public void handleProposalMessage(final Proposal msg) {
    LOG.debug(
        "Received a proposal message. round={}. author={}",
        roundState.getRoundIdentifier(),
        msg.getAuthor());
    final QbftBlock block = msg.getSignedPayload().getPayload().getProposedBlock();
    if (updateStateWithProposedBlock(msg)) {
      sendPrepare(block);
    }
  }
Handle proposal message.

@param msg the msg
consensus/qbft-core/src/main/java/org/hyperledger/besu/consensus/qbft/core/statemachine/QbftRound.java