code: def piecewise_constant(self, index: int, num_steps: int) -> List:
      target = []
      for j in range(num_steps):
          if j < self.num_training_steps:
              constant = self.determine_constant(index=index)
          else:
              constant = self.determine_constant(index=index, seed=2)
          target.append(constant)
      return target
  
imports: import math
  import random
  from abc import abstractmethod
  from typing import Callable, Dict, List, NamedTuple, Optional, Tuple, Union, cast
  import numpy
  import pandas
  from pandas.tseries.frequencies import to_offset
  from pandas.tseries.offsets import BaseOffset, Week
  from gluonts.dataset.artificial.recipe import BinaryHolidays, BinaryMarkovChain, Constant, ForEachCat, Lag, LinearTrend, RandomCat, RandomGaussian, Stack, generate, take_as_list
  from gluonts.dataset.common import BasicFeatureInfo, CategoricalFeatureInfo, DataEntry, Dataset, ListDataset, MetaData, TrainDatasets
  from gluonts.dataset.field_names import FieldName
  from gluonts.dataset.stat import DatasetStatistics, calculate_dataset_statistics
label_desc: Use image node_id 5 for calling the ConstantDataset obj's underlying member method code with example usage: obj.piecewise_constant(index, num_steps) and returns: target