code: def _check_roundtrip_fixed(dip, tmp_path):
      """Check roundtrip IO for fixed dipoles."""
      dip.save(tmp_path / "test-dip.fif.gz")
      dip_read = read_dipole(tmp_path / "test-dip.fif.gz")
      assert_allclose(dip_read.data, dip_read.data)
      assert_allclose(dip_read.times, dip.times, atol=1e-8)
      assert (
          dip_read.info["xplotter_layout"]
          == dip.info["xplotter_layout"]
      )
      assert dip_read.ch_names == dip.ch_names
      for ch_1, ch_2 in zip(dip_read.info["chs"], dip.info["chs"]):
          assert ch_1["ch_name"] == ch_2["ch_name"]
          for key in (
              "loc",
              "kind",
              "unit_mul",
              "range",
              "coord_frame",
              "unit",
              "cal",
              "coil_type",
              "scanno",
              "logno",
          ):
              assert_allclose(ch_1[key], ch_2[key], err_msg=key)
  
imports: import os
  import matplotlib.pyplot
  import numpy
  import pytest
  from numpy.testing import assert_allclose, assert_array_equal, assert_array_less
  from mne import Dipole, DipoleFixed, Epochs, Evoked, EvokedArray, SourceEstimate, convert_forward_solution, fit_dipole, head_to_mni, make_ad_hoc_cov, make_fixed_length_events, make_forward_solution, make_sphere_model, pick_info, pick_types, read_cov, read_dipole, read_evokeds, read_forward_solution, read_source_spaces, transform_surface_to, write_evokeds
  from mne._fiff.constants import FIFF
  from mne.bem import _bem_find_surface, read_bem_solution
  from mne.datasets import testing
  from mne.dipole import _BDIP_ERROR_KEYS, get_phantom_dipoles
  from mne.io import read_raw_ctf, read_raw_fif
  from mne.proj import make_eeg_average_ref_proj
  from mne.simulation import simulate_evoked
  from mne.surface import _compute_nearest
  from mne.transforms import _get_trans, apply_trans
  from mne.utils import _record_warnings, requires_mne, run_subprocess
label_desc: Use image node_id 12 for calling a global function with example usage: _check_roundtrip_fixed(dip, tmp_path) without return types