@Override
  public String toString() {
    return "IbftLegacyExtraData{" + super.toString() + ", proposerSeal=" + proposerSeal + '}';
  }
Gets proposer seal.

@return the proposer seal
consensus/ibftlegacy/src/main/java/org/hyperledger/besu/consensus/ibftlegacy/IbftLegacyExtraData.java