code: def test_lstm_forecaster_import(self):
      from bigdl.chronos.forecaster.pytorch import LSTMForecaster
  
      assert isinstance(LSTMForecaster, LazyImport)
  
      lstm = LSTMForecaster(
          input_feature_num=1, output_feature_num=1, past_seq_len=48
      )
      from bigdl.chronos.forecaster.lstm_forecaster import (
          LSTMForecaster,
      )
  
      assert not isinstance(LSTMForecaster, LazyImport)
      assert isinstance(lstm, LSTMForecaster)
  
file_path: BigDL/python/chronos/test/bigdl/chronos/forecaster/test_pytorch.py
imports: from unittest import TestCase
  from bigdl.chronos.utils import LazyImport
  from ..None import op_torch
label_desc: Use image node_id 4 for calling the TestChronosModelPytorch obj's underlying member method code with example usage: obj.test_lstm_forecaster_import() without return types