@Override
  public boolean includeInLightValidation() {
    return false;
  }
Responsible for determining the validity of the extra data field. Ensures:

<ul>
  <li>Bytes in the extra data field can be decoded as per Clique specification
  <li>Proposer (derived from the proposerSeal) is a member of the validators
  <li>Validators are only validated on epoch blocks.
</ul>

@param header the block header containing the extraData to be validated.
@return True if the extraData successfully produces an CliqueExtraData object, false otherwise
consensus/clique/src/main/java/org/hyperledger/besu/consensus/clique/headervalidationrules/CliqueExtraDataValidationRule.java