public static Collection<Address> getValidatorsForBlock(
      final ProtocolContext protocolContext, final BlockHeader parentHeader) {
    return protocolContext
        .getConsensusContext(BftContext.class)
        .getValidatorProvider()
        .getValidatorsForBlock(parentHeader);
  }
Get the list of validators that are applicable for the given block

@param protocolContext the protocol context
@param parentHeader the parent header
@return the list of validators
consensus/ibft/src/main/java/org/hyperledger/besu/consensus/ibft/validation/MessageValidatorFactory.java