code: def _compare_io(inv_op, *, out_file_ext=".fif", tmp_path):
      """Compare inverse IO."""
      if out_file_ext == ".fif":
          out_file = tmp_path / "test-inv.fif"
      elif out_file_ext == ".gz":
          out_file = tmp_path / "test-inv.fif.gz"
      else:
          raise ValueError("IO test could not complete")
      # Test io operations
      inv_init = copy.deepcopy(inv_op)
      write_inverse_operator(out_file, inv_op, overwrite=True)
      read_inv_op = read_inverse_operator(out_file)
      _compare(inv_init, read_inv_op)
      _compare(inv_init, inv_op)
  
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 5 for calling a global function with example usage: _compare_io(inv_op) without return types