code: public Destination.DestinationType getDestinationType(int branches, int index) {
      return Destination.DestinationType.valueOf(this.taskState.getProp(
          ForkOperatorUtils.getPropertyNameForBranch(ConfigurationKeys.WRITER_DESTINATION_TYPE_KEY, branches, index),
          Destination.DestinationType.HDFS.name()));
    }
docs: Get the writer {@link Destination.DestinationType}.
  
  @param branches number of forked branches
  @param index branch index
  @return writer {@link Destination.DestinationType}