code: def test_check_freq_unit_at_most_day():
      # tests no error
      check_freq_unit_at_most_day("D", "name")
      check_freq_unit_at_most_day("50H", "name")
      # tests ValueError
      with pytest.raises(
          ValueError,
          match="In name, the maximal unit is 'D', "
          "i.e., you may use units no more than 'D' such as"
          "'10D', '5H', '100T', '200S'. The reason is that 'W', 'M' "
          "or higher has either cycles or indefinite number of days, "
          "thus is not parsable by pandas as timedelta.",
      ):
          check_freq_unit_at_most_day("2M", "name")
  
imports: from datetime import datetime
  import numpy
  import pandas
  import pytest
  from greykite.algo.changepoint.adalasso.changepoints_utils import adaptive_lasso_cv
  from greykite.algo.changepoint.adalasso.changepoints_utils import build_seasonality_feature_df_from_detection_result
  from greykite.algo.changepoint.adalasso.changepoints_utils import build_seasonality_feature_df_with_changes
  from greykite.algo.changepoint.adalasso.changepoints_utils import build_trend_feature_df_with_changes
  from greykite.algo.changepoint.adalasso.changepoints_utils import check_freq_unit_at_most_day
  from greykite.algo.changepoint.adalasso.changepoints_utils import combine_detected_and_custom_trend_changepoints
  from greykite.algo.changepoint.adalasso.changepoints_utils import compute_fitted_components
  from greykite.algo.changepoint.adalasso.changepoints_utils import compute_min_changepoint_index_distance
  from greykite.algo.changepoint.adalasso.changepoints_utils import estimate_seasonality_with_detected_changepoints
  from greykite.algo.changepoint.adalasso.changepoints_utils import estimate_trend_with_detected_changepoints
  from greykite.algo.changepoint.adalasso.changepoints_utils import filter_changepoints
  from greykite.algo.changepoint.adalasso.changepoints_utils import find_neighbor_changepoints
  from greykite.algo.changepoint.adalasso.changepoints_utils import get_changes_from_beta
  from greykite.algo.changepoint.adalasso.changepoints_utils import get_seasonality_changepoint_df_cols
  from greykite.algo.changepoint.adalasso.changepoints_utils import get_seasonality_changes_from_adaptive_lasso
  from greykite.algo.changepoint.adalasso.changepoints_utils import get_trend_changepoint_dates_from_cols
  from greykite.algo.changepoint.adalasso.changepoints_utils import get_trend_changes_from_adaptive_lasso
  from greykite.algo.changepoint.adalasso.changepoints_utils import get_yearly_seasonality_changepoint_dates_from_freq
  from greykite.algo.changepoint.adalasso.changepoints_utils import plot_change
  from greykite.common.testing_utils import generate_df_for_tests
label_desc: Use image node_id 2 for calling a global function with example usage: test_check_freq_unit_at_most_day() without return types