code: def _build_division_map_ref(id_tracker, batch_size, n_sub):
      """Reference implementation for _build_division_map in pure Python"""
      id_to_model = np.zeros(batch_size, dtype=np.int32)
      id_to_pos = np.zeros(batch_size, dtype=np.int32)
      for i in range(n_sub):
          id_to_model[id_tracker[i]] = i
          for j in range(len(id_tracker[i])):
              id_to_pos[id_tracker[i][j]] = j
      return id_to_model, id_to_pos
  
file_path: cuml/python/cuml/tests/test_auto_arima.py
imports: from cuml.internals.input_utils import input_to_cuml_array
  from cuml.tsa import auto_arima
  import pytest
  from cuml.internals.safe_imports import cpu_only_import
label_desc: Use image node_id 1 for calling a global function with example usage: _build_division_map_ref(id_tracker, batch_size, n_sub) and returns: id_to_model,  id_to_pos