code: def test_autoformer_forecaster_lookback_equals_to_one(self):
      # from tsdataset
      df = get_ts_df()
      target = ["value", "extra feature"]
      tsdata_train, tsdata_val, tsdata_test = TSDataset.from_pandas(
          df,
          dt_col="datetime",
          target_col=target,
          with_split=True,
          test_ratio=0.1,
          val_ratio=0.1,
      )
      with pytest.raises(RuntimeError):
          forecaster = AutoformerForecaster.from_tsdataset(
              tsdata_train, past_seq_len=1, future_seq_len=5
          )
  
      # normal definition
      with pytest.raises(RuntimeError):
          forecaster = AutoformerForecaster(
              past_seq_len=1,
              future_seq_len=5,
              input_feature_num=2,
              output_feature_num=2,
              label_len=12,
              freq="s",
          )
  
imports: import numpy
  import pandas
  import tempfile
  import os
  from bigdl.chronos.utils import LazyImport
  from bigdl.chronos.data import TSDataset
  from unittest import TestCase
  import pytest
  from ..None import op_torch, op_automl
label_desc: Use image node_id 18 for calling the TestChronosModelAutoformerForecaster obj's underlying member method code with example usage: obj.test_autoformer_forecaster_lookback_equals_to_one() without return types