private ValidatorProvider resolveValidatorProvider(final long block) {
    final ForkSpec<QbftConfigOptions> fork = forksSchedule.getFork(block);
    return fork.getValue().isValidatorContractMode()
        ? transactionValidatorProvider
        : blockValidatorProvider;
  }
Instantiates a new Forking validator provider.

@param blockchain the blockchain
@param forksSchedule the forks schedule
@param blockValidatorProvider the block validator provider
@param transactionValidatorProvider the transaction validator provider
consensus/qbft/src/main/java/org/hyperledger/besu/consensus/qbft/validator/ForkingValidatorProvider.java