@Override
  public QbftBlockHeader getParentBlockHeader() {
    return parentHeader;
  }
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 qbftRound The current round
consensus/qbft-core/src/main/java/org/hyperledger/besu/consensus/qbft/core/statemachine/QbftBlockHeightManager.java