@Override
  public long getBlockPeriodMilliseconds() {
    return JsonUtil.getLong(
        bftConfigRoot, "xblockperiodmilliseconds", DEFAULT_BLOCK_PERIOD_MILLISECONDS);
  }
Instantiates a new Json bft config options.

@param bftConfigRoot the bft config root
config/src/main/java/org/hyperledger/besu/config/JsonBftConfigOptions.java