code: def setup_test_case():
      n_groups = 5
      len_ts = 10
      times = (
          pd.concat(
              [
                  pd.DataFrame(
                      generate_index(
                          start=pd.Timestamp(2010, 1, 1), length=len_ts
                      )
                  )
              ]
              * n_groups,
              axis=0,
          )
          .reset_index(drop=True)
          .rename(columns={0: "times"})
      )
  
      x = pd.DataFrame(
          np.random.randn(n_groups * len_ts, 3), columns=["a", "b", "c"]
      )
      static_multivar = pd.DataFrame(
          [
              [i, 0 if j < (len_ts // 2) else 1]
              for i in range(n_groups)
              for j in range(len_ts)
          ],
          columns=["st1", "st2"],
      )
  
      df_long_multi = pd.DataFrame(
          pd.concat([times, x, static_multivar], axis=1),
      )
      df_long_multi.loc[:, "constant"] = 1
      df_long_uni = df_long_multi.drop(columns=["st2"])
      return n_groups, len_ts, df_long_uni, df_long_multi
  
imports: import copy
  import os
  import numpy
  import pandas
  import pytest
  from darts import TimeSeries, concatenate
  from darts.dataprocessing.transformers import BoxCox, Scaler
  from darts.timeseries import DEFAULT_GLOBAL_STATIC_COV_NAME, STATIC_COV_TAG
  from darts.utils.timeseries_generation import generate_index, linear_timeseries
label_desc: Use image node_id 1 for calling a global function with example usage: setup_test_case() and returns: n_groups,  len_ts,  df_long_uni,  df_long_multi