code: def test_io_inverse_operator(tmp_path):
      """Test IO of inverse_operator."""
      inverse_operator = read_inverse_operator(fname_inv)
      x = repr(inverse_operator)
      assert x
      assert isinstance(inverse_operator["noise_cov"], Covariance)
      # just do one example for .gz, as it should generalize
      _compare_io(
          inverse_operator, out_file_ext=".gz", tmp_path=tmp_path
      )
  
      # test warnings on bad filenames
      inv_badname = tmp_path / "test-bad-name.fif.gz"
      with pytest.warns(RuntimeWarning, match="-inv.fif"):
          write_inverse_operator(inv_badname, inverse_operator)
      with pytest.warns(RuntimeWarning, match="-inv.fif"):
          read_inverse_operator(inv_badname)
  
      # make sure we can write and read
      inv_fname = tmp_path / "test-inv.fif"
      args = (10, 1.0 / 9.0, "dSPM")
      inv_prep = prepare_inverse_operator(inverse_operator, *args)
      write_inverse_operator(inv_fname, inv_prep)
      inv_read = read_inverse_operator(inv_fname)
      _compare(inverse_operator, inv_read)
      inv_read_prep = prepare_inverse_operator(inv_read, *args)
      _compare(inv_prep, inv_read_prep)
      inv_prep_prep = prepare_inverse_operator(inv_prep, *args)
      _compare(inv_prep, inv_prep_prep)
  
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 26 for calling a global function with example usage: test_io_inverse_operator(tmp_path) without return types