code: def test_plot_alignment_fnirs(renderer, tmp_path):
      """Test fNIRS plotting."""
      # Here we use subjects_dir=tmp_path, since no surfaces should actually
      # be loaded!
  
      # fNIRS (default is pairs)
      info = read_raw_nirx(nirx_fname).info
      assert info["nchan"] == 26
      kwargs = dict(
          trans="fsaverage",
          subject="fsaverage",
          surfaces=(),
          verbose=True,
          subjects_dir=tmp_path,
      )
      with catch_logging() as log:
          fig = plot_alignment(info, **kwargs)
      log = log.getvalue()
      assert f'fnirs_cw_amplitude: {info["nchan"]}' in log
      _assert_n_actors(fig, renderer, info["nchan"])
  
      fig = plot_alignment(
          info, fnirs=["channels", "sources", "detectors"], **kwargs
      )
      _assert_n_actors(fig, renderer, 3)
  
imports: from pathlib import Path
  import matplotlib.pyplot
  import numpy
  import pytest
  from matplotlib.colors import Colormap
  from matplotlib.figure import Figure
  from numpy.testing import assert_allclose, assert_array_equal
  from mne import MixedSourceEstimate, SourceEstimate, convert_forward_solution, make_field_map, make_sphere_model, pick_info, pick_types, read_dipole, read_evokeds, read_forward_solution, read_trans, setup_volume_source_space, use_coil_def
  from mne._fiff._digitization import write_dig
  from mne._fiff.constants import FIFF
  from mne.bem import read_bem_solution, read_bem_surfaces
  from mne.datasets import testing
  from mne.defaults import DEFAULTS
  from mne.io import read_info, read_raw_bti, read_raw_ctf, read_raw_kit, read_raw_nirx
  from mne.minimum_norm import apply_inverse
  from mne.source_estimate import _BaseVolSourceEstimate
  from mne.source_space import read_source_spaces
  from mne.transforms import Transform
  from mne.utils import _record_warnings, catch_logging
  from mne.viz import Brain, EvokedField, Figure3D, link_brains, mne_analyze_colormap, plot_alignment, plot_brain_colorbar, plot_head_positions, plot_source_estimates, plot_sparse_source_estimates, snapshot_brain_montage
  from mne.viz._3d import _get_map_ticks, _linearize_map, _process_clim
  from mne.viz.utils import _fake_click, _fake_keypress, _fake_scroll, _get_cmap
label_desc: Use image node_id 9 for calling a global function with example usage: test_plot_alignment_fnirs(renderer, tmp_path) without return types