code: def test_no_conversion(pdf, config, hs, exported):
      """Test bti no-conversion option."""
      get_info = partial(
          _get_bti_info,
          rotation_x=0.0,
          translation=(0.0, 0.02, 0.11),
          convert=False,
          ecg_ch="E31",
          eog_ch=("E63", "E64"),
          rename_channels=False,
          sort_by_ch_name=False,
      )
  
      raw_info, _ = get_info(pdf, config, hs, convert=False)
      raw_info_con = read_raw_bti(
          pdf_fname=pdf,
          config_fname=config,
          head_shape_fname=hs,
          convert=True,
          preload=False,
      ).info
  
      pick_info(
          raw_info_con,
          pick_types(raw_info_con, meg=True, ref_meg=True),
          copy=False,
      )
      pick_info(
          raw_info,
          pick_types(raw_info, meg=True, ref_meg=True),
          copy=False,
      )
      bti_info = _read_bti_header(pdf, config)
      dev_ctf_t = _correct_trans(bti_info["bti_transform"][0])
      assert_array_equal(dev_ctf_t, raw_info["dev_ctf_t"]["trans"])
      assert_array_equal(raw_info["dev_head_t"]["trans"], np.eye(4))
      assert_array_equal(raw_info["ctf_head_t"]["trans"], np.eye(4))
  
      nasion, lpa, rpa, hpi, dig_points = _read_head_shape(hs)
      dig, t, _ = _make_bti_dig_points(
          nasion,
          lpa,
          rpa,
          hpi,
          dig_points,
          convert=False,
          use_hpi=False,
      )
  
      assert_array_equal(t["trans"], np.eye(4))
  
      for ii, (old, new, con) in enumerate(
          zip(dig, raw_info["dig"], raw_info_con["dig"])
      ):
          assert_equal(old["ident"], new["ident"])
          assert_array_equal(old["r"], new["r"])
          assert not np.allclose(old["r"], con["r"])
  
          if ii > 10:
              break
  
      ch_map = {ch["chan_label"]: ch["loc"] for ch in bti_info["chs"]}
  
      for ii, ch_label in enumerate(raw_info["ch_names"]):
          if not ch_label.startswith("A"):
              continue
          t1 = ch_map[
              ch_label
          ]  # correction already performed in bti_info
          t2 = raw_info["chs"][ii]["loc"]
          t3 = raw_info_con["chs"][ii]["loc"]
          assert_allclose(t1, t2, atol=1e-15)
          assert not np.allclose(t1, t3)
          idx_a = raw_info_con["ch_names"].index("MEG 001")
          idx_b = raw_info["ch_names"].index("A22")
          assert_equal(
              raw_info_con["chs"][idx_a]["coord_frame"],
              FIFF.FIFFV_COORD_DEVICE,
          )
          assert_equal(
              raw_info["chs"][idx_b]["coord_frame"],
              FIFF.FIFFV_MNE_COORD_4D_HEAD,
          )
  
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 8 for calling a global function with example usage: test_no_conversion(pdf, config, hs, exported) without return types