code: def test_pick_channels_regexp():
      """Test pick with regular expression."""
      ch_names = ["MEG 2331", "MEG 2332", "MEG 2333"]
      assert_array_equal(
          pick_channels_regexp(ch_names, "MEG ...1"), [0]
      )
      assert_array_equal(
          pick_channels_regexp(ch_names, "MEG ...[2-3]"), [1, 2]
      )
      assert_array_equal(
          pick_channels_regexp(ch_names, "MEG *"), [0, 1, 2]
      )
  
imports: from copy import deepcopy
  from pathlib import Path
  import numpy
  import pytest
  from numpy.testing import assert_array_equal
  from mne import Epochs, channel_indices_by_type, channel_type, create_info, make_ad_hoc_cov, pick_channels, pick_channels_cov, pick_channels_regexp, pick_info, pick_types, pick_types_forward, read_forward_solution, rename_channels
  from mne._fiff.constants import FIFF
  from mne._fiff.pick import _DATA_CH_TYPES_SPLIT, _contains_ch_type, _picks_by_type, _picks_to_idx, get_channel_type_constants
  from mne.channels import make_standard_montage
  from mne.datasets import testing
  from mne.io import RawArray, read_info, read_raw_bti, read_raw_fif, read_raw_kit
  from mne.preprocessing import compute_current_source_density
  from mne.utils import assert_object_equal, catch_logging
label_desc: Use image node_id 5 for calling a global function with example usage: test_pick_channels_regexp() without return types