code: def test_bti_ch_data(fname, preload):
      """Test for gh-6048."""
      read_raw_bti(fname, preload=preload)
  
imports: import os
  from collections import Counter
  from functools import partial, reduce
  from io import BytesIO
  from pathlib import Path
  import numpy
  import pytest
  from numpy.testing import assert_allclose, assert_array_almost_equal, assert_array_equal, assert_equal
  import mne
  from mne import pick_info, pick_types
  from mne._fiff._digitization import _make_bti_dig_points
  from mne._fiff.constants import FIFF
  from mne.datasets import testing
  from mne.io import read_raw_bti, read_raw_fif
  from mne.io.bti.bti import _check_nan_dev_head_t, _convert_coil_trans, _correct_trans, _get_bti_dev_t, _get_bti_info, _loc_to_coil_trans, _read_bti_header, _read_config, _read_head_shape, _rename_channels
  from mne.io.tests.test_raw import _test_raw_reader
  from mne.transforms import Transform, combine_transforms, invert_transform
  from mne.utils import assert_dig_allclose
label_desc: Use image node_id 12 for calling a global function with example usage: test_bti_ch_data(fname, preload) without return types