How to use

headerValidators

method

in

org.ethereum.config.BlockchainConfig

@Override
public List<Pair<Long, BlockHeaderValidator>> headerValidators() {
  return parent.headerValidators();
}

  @Override
  public ValidationResult validate(BlockHeader header) {
    List<Pair<Long, BlockHeaderValidator>> validators = blockchainConfig.getConfigForBlock(header.getNumber()).headerValidators();
    for (Pair<Long, BlockHeaderValidator> pair : validators) {
      if (header.getNumber() == pair.getLeft()) {
        ValidationResult result = pair.getRight().validate(header);
        if (!result.success) {
          return fault("Block " + header.getNumber() + " header constraint violated. " + result.error);
        }
      }
    }

    return Success;
  }
}

    getConfigForBlock(blockNumber).headerValidators();
for (Pair<Long, BlockHeaderValidator> validator : validators) {
  if (validator.getLeft() <= getBestKnownBlock().getNumber()) {

for (GenesisConfig.HashValidator validator : genesisJson.getConfig().headerValidators) {
  BlockHeaderValidator headerValidator = new BlockHeaderValidator(new BlockCustomHashRule(ByteUtil.hexStringToBytes(validator.hash)));
  blockchainConfig.getConfigForBlock(validator.number).headerValidators().add(
      Pair.of(validator.number, headerValidator));