public BftExtraData decode(final BlockHeader blockHeader) {
    final Object inputExtraData = blockHeader.getParsedExtraData();
    if (inputExtraData instanceof BftExtraData) {
      return (BftExtraData) inputExtraData;
    }
    LOG.warn(
        "Expected a BftExtraData instance but got {}. Reparsing required.",
        inputExtraData != null ? inputExtraData.getClass().getName() : "null");
    return decodeRaw(blockHeader.getExtraData());
  }
Decode.

@param blockHeader the block header
@return the bft extra data
consensus/common/src/main/java/org/hyperledger/besu/consensus/common/bft/BftExtraDataCodec.java