public Collection<Address> getValidators(final long blockNumber, final Address contractAddress) {
    return callFunction(blockNumber, getValidatorsFunction, contractAddress)
        .map(this::parseGetValidatorsResult)
        .orElseThrow(() -> new IllegalStateException(CONTRACT_ERROR_MSG));
  }
Gets validators.

@param blockNumber the block number
@param contractAddress the contract address
@return the validators
consensus/qbft/src/main/java/org/hyperledger/besu/consensus/qbft/validator/ValidatorContractController.java