private void startNewRound(final int roundNumber) {
    LOG.debug("Starting new round {}", roundNumber);
    if (futureRoundStateBuffer.containsKey(roundNumber)) {
      currentRound =
          roundFactory.createNewRoundWithState(
              parentHeader, futureRoundStateBuffer.get(roundNumber));
      futureRoundStateBuffer.keySet().removeIf(k -> k <= roundNumber);
    } else {
      currentRound = roundFactory.createNewRound(parentHeader, roundNumber);
    }
    // discard roundChange messages from the current and previous rounds
    roundChangeManager.discardRoundsPriorTo(currentRound.getRoundIdentifier());
  }
If the list of validators for the next block to be proposed/imported has changed from the
previous block, log the change. Only log for round 0 (i.e. once per block).

@param ibftRound The current round
consensus/ibft/src/main/java/org/hyperledger/besu/consensus/ibft/statemachine/IbftBlockHeightManager.java