code: def test_apply_mne_inverse_fixed_raw():
      """Test MNE with fixed-orientation inverse operator on Raw."""
      raw = read_raw_fif(fname_raw)
      start = 3
      stop = 10
      _, times = raw[0, start:stop]
      label_lh = read_label(str(fname_label) % "Aud-lh")
  
      # create a fixed-orientation inverse operator
      fwd = read_forward_solution_meg(
          fname_fwd, force_fixed=False, surf_ori=True
      )
      noise_cov = read_cov(fname_cov)
      pytest.raises(
          ValueError,
          make_inverse_operator,
          raw.info,
          fwd,
          noise_cov,
          loose=1.0,
          fixed=True,
      )
      inv_op = make_inverse_operator(
          raw.info, fwd, noise_cov, fixed=True, use_cps=True
      )
  
      inv_op2 = prepare_inverse_operator(
          inv_op, nave=1, lambda2=lambda2, method="dSPM"
      )
      stc = apply_inverse_raw(
          raw,
          inv_op2,
          lambda2,
          "dSPM",
          label=label_lh,
          start=start,
          stop=stop,
          nave=1,
          pick_ori=None,
          buffer_size=None,
          prepared=True,
      )
  
      stc2 = apply_inverse_raw(
          raw,
          inv_op2,
          lambda2,
          "dSPM",
          label=label_lh,
          start=start,
          stop=stop,
          nave=1,
          pick_ori=None,
          buffer_size=3,
          prepared=True,
      )
  
      stc3 = apply_inverse_raw(
          raw,
          inv_op,
          lambda2,
          "dSPM",
          label=label_lh,
          start=start,
          stop=stop,
          nave=1,
          pick_ori=None,
          buffer_size=None,
      )
  
      assert stc.subject == "sample"
      assert stc2.subject == "sample"
      assert_array_almost_equal(stc.times, times)
      assert_array_almost_equal(stc2.times, times)
      assert_array_almost_equal(stc3.times, times)
      assert_array_almost_equal(stc.data, stc2.data)
      assert_array_almost_equal(stc.data, stc3.data)
  
imports: import copy
  import re
  from pathlib import Path
  import numpy
  import pytest
  from numpy.testing import assert_allclose, assert_array_almost_equal, assert_array_equal, assert_array_less, assert_equal
  from scipy import sparse
  import mne
  from mne import Covariance, EvokedArray, SourceEstimate, combine_evoked, compute_raw_covariance, convert_forward_solution, make_ad_hoc_cov, make_forward_solution, make_sphere_model, pick_channels_forward, pick_types, pick_types_forward, read_cov, read_evokeds, read_forward_solution
  from mne.datasets import testing
  from mne.epochs import Epochs, EpochsArray, make_fixed_length_epochs
  from mne.event import read_events
  from mne.forward import apply_forward, is_fixed_orient, restrict_forward_to_stc
  from mne.io import read_info, read_raw_fif
  from mne.label import label_sign_flip, read_label
  from mne.minimum_norm import INVERSE_METHODS, apply_inverse, apply_inverse_cov, apply_inverse_epochs, apply_inverse_raw, apply_inverse_tfr_epochs, compute_rank_inverse, make_inverse_operator, prepare_inverse_operator, read_inverse_operator, write_inverse_operator
  from mne.source_estimate import VolSourceEstimate, read_source_estimate
  from mne.source_space._source_space import _get_src_nn
  from mne.surface import _normal_orth
  from mne.time_frequency import EpochsTFR
  from mne.utils import _record_warnings, catch_logging
label_desc: Use image node_id 29 for calling a global function with example usage: test_apply_mne_inverse_fixed_raw() without return types