code: def _multi_setup(self):
      x = self.data.to_pd()
      self.data = TimeSeries.from_pd(
          pd.DataFrame(
              np.concatenate((x.values, x.values * 2), axis=1),
              columns=["A", "B"],
              index=x.index,
          )
      )
      self.train_data = self.data[: len(self.train_data)]
      self.test_data = self.data[len(self.train_data) :]
      self.model.config.target_seq_index = 0
  
file_path: merlion/tests/forecast/test_ets.py
imports: import logging
  from os.path import abspath, dirname, join
  import sys
  import unittest
  import pandas
  import numpy
  from merlion.evaluate.forecast import ForecastMetric
  from merlion.models.forecast.ets import ETSConfig, ETS
  from merlion.utils.time_series import TimeSeries, to_pd_datetime
label_desc: Use image node_id 2 for calling the TestETS obj's underlying member method code with example usage: obj._multi_setup() without return types