code: def test_Transformation():
      train_length = 100
      ds = gluonts.dataset.common.ListDataset(
          [{"start": "2012-01-01", "target": [0.2] * train_length}],
          freq="1D",
      )
  
      pred_length = 10
  
      t = transform.Chain(
          [
              transform.AddTimeFeatures(
                  start_field=FieldName.START,
                  target_field=FieldName.TARGET,
                  output_field="time_feat",
                  time_features=[
                      time_feature.day_of_week,
                      time_feature.day_of_month,
                      time_feature.month_of_year,
                  ],
                  pred_length=pred_length,
              ),
              transform.AddAgeFeature(
                  target_field=FieldName.TARGET,
                  output_field="age",
                  pred_length=pred_length,
                  log_scale=True,
              ),
              transform.AddObservedValuesIndicator(
                  target_field=FieldName.TARGET,
                  output_field="observed_values",
              ),
              transform.VstackFeatures(
                  output_field="dynamic_feat",
                  input_fields=["age", "time_feat"],
                  drop_inputs=True,
              ),
              transform.InstanceSplitter(
                  target_field=FieldName.TARGET,
                  is_pad_field=FieldName.IS_PAD,
                  start_field=FieldName.START,
                  forecast_start_field=FieldName.FORECAST_START,
                  instance_sampler=transform.ExpectedNumInstanceSampler(
                      num_instances=4
                  ),
                  past_length=train_length,
                  future_length=pred_length,
                  time_series_fields=[
                      "dynamic_feat",
                      "observed_values",
                  ],
              ),
          ]
      )
  
      assert_serializable(t)
  
      for u in t(iter(ds), is_train=True):
          print(u)
  
imports: from typing import Tuple, List
  import numpy
  import pandas
  from pandas.tseries.frequencies import to_offset
  import pytest
  import gluonts
  from gluonts import time_feature, transform
  from gluonts.core import fqname_for
  from gluonts.core.serde import dump_json, load_json
  from gluonts.dataset.common import DataEntry, ListDataset
  from gluonts.dataset.field_names import FieldName
  from gluonts.dataset.stat import ScaleHistogram, calculate_dataset_statistics
  from gluonts.transform import CausalMeanValueImputation, DummyValueImputation, LastValueImputation, MeanValueImputation, RollingMeanValueImputation, Valmap
  from gluonts.transform.convert import ToIntervalSizeFormat, erf, erfinv
  from gluonts.transform.feature import CountTrailingZeros
label_desc: Use image node_id 8 for calling a global function with example usage: test_Transformation() without return types