public static CliqueExtraData decode(final BlockHeader header) {
    final Object inputExtraData = header.getParsedExtraData();
    if (inputExtraData instanceof CliqueExtraData) {
      return (CliqueExtraData) inputExtraData;
    }
    LOG.warn(
        "Expected a CliqueExtraData instance but got {}. Reparsing required.",
        inputExtraData != null ? inputExtraData.getClass().getName() : "null");
    return decodeRaw(header);
  }
Decode header to get clique extra data.

@param header the header
@return the clique extra data
consensus/clique/src/main/java/org/hyperledger/besu/consensus/clique/CliqueExtraData.java