code: public boolean isSet(_Fields field) {
      if (field == null) {
        throw new IllegalArgumentException();
      }
  
      switch (field) {
      case NAME:
        return isSetName();
      case STRATEGY_CLASS:
        return isSetStrategy_class();
      case STRATEGY_OPTIONS:
        return isSetStrategy_options();
      case REPLICATION_FACTOR:
        return isSetReplication_factor();
      case CF_DEFS:
        return isSetCf_defs();
      case DURABLE_WRITES:
        return isSetDurable_writes();
      }
      throw new IllegalStateException();
    }
docs: Returns true if field corresponding to fieldID is set (has been assigned a value) and false otherwise