code: def test_nirx_15_0():
      """Test reading NIRX files."""
      raw = read_raw_nirx(fname_nirx_15_0, preload=True)
  
      # Test data import
      assert raw._data.shape == (20, 92)
      assert raw.info["sfreq"] == 6.25
      assert raw.info["meas_date"] == dt.datetime(
          2019, 10, 27, 13, 53, 34, 209000, tzinfo=dt.timezone.utc
      )
  
      # Test channel naming
      assert raw.info["ch_names"][:12] == [
          "S1_D1 760",
          "S1_D1 850",
          "S2_D2 760",
          "S2_D2 850",
          "S3_D3 760",
          "S3_D3 850",
          "S4_D4 760",
          "S4_D4 850",
          "S5_D5 760",
          "S5_D5 850",
          "S6_D6 760",
          "S6_D6 850",
      ]
  
      # Test info import
      assert raw.info["subject_info"] == {
          "birthday": (2004, 10, 27),
          "first_name": "NIRX",
          "last_name": "Test",
          "sex": FIFF.FIFFV_SUBJ_SEX_UNKNOWN,
          "his_id": "NIRX_Test",
      }
  
      # Test trigger events
      assert_array_equal(
          raw.annotations.description, ["1.0", "2.0", "2.0"]
      )
  
      # Test location of detectors
      allowed_dist_error = 0.0002
      locs = [ch["loc"][6:9] for ch in raw.info["chs"]]
      head_mri_t, _ = _get_trans("fsaverage", "head", "mri")
      mni_locs = apply_trans(head_mri_t, locs)
  
      assert raw.info["ch_names"][0][3:5] == "D1"
      assert_allclose(
          mni_locs[0],
          [0.0287, -0.1143, -0.0332],
          atol=allowed_dist_error,
      )
  
      assert raw.info["ch_names"][15][3:5] == "D8"
      assert_allclose(
          mni_locs[15],
          [-0.0693, -0.0480, 0.0657],
          atol=allowed_dist_error,
      )
  
      # Test distance between optodes matches values from
      allowed_distance_error = 0.0002
  
      assert_allclose(
          source_detector_distances(raw.copy().pick("S1_D1 760").info),
          [0.0300],
          atol=allowed_distance_error,
      )
      assert_allclose(
          source_detector_distances(raw.copy().pick("S7_D7 760").info),
          [0.0392],
          atol=allowed_distance_error,
      )
  
imports: import datetime
  import os
  import shutil
  import numpy
  import pytest
  from numpy.testing import assert_allclose, assert_array_equal
  from mne import pick_types
  from mne._fiff.constants import FIFF
  from mne.datasets.testing import data_path, requires_testing_data
  from mne.io import read_raw_nirx
  from mne.io.tests.test_raw import _test_raw_reader
  from mne.preprocessing import annotate_nan
  from mne.preprocessing.nirs import _reorder_nirx, short_channels, source_detector_distances
  from mne.transforms import _get_trans, apply_trans
label_desc: Use image node_id 15 for calling a global function with example usage: test_nirx_15_0() without return types