code: def test_make_forward_solution_openmeeg(n_layers):
      """Test making M-EEG forward solution from OpenMEEG."""
      solver = "openmeeg"
      bem_surfaces = read_bem_surfaces(fname_bem)
      raw = read_raw_fif(fname_raw)
      n_sensors = 366
      ch_types = ["eeg", "meg"]
      if n_layers == 1:
          ch_types = ["meg"]
          bem_surfaces = bem_surfaces[-1:]
          assert bem_surfaces[0]["id"] == FIFF.FIFFV_BEM_SURF_ID_BRAIN
          n_sensors = 306
      raw.pick(ch_types)
      n_sources_kept = 501 // 3
      fwds = dict()
      for solver in ["openmeeg", "mne"]:
          bem = make_bem_solution(bem_surfaces, solver=solver)
          assert bem["solver"] == solver
          with catch_logging() as log:
              # make sure everything can be path-like (gh #10872)
              fwd = make_forward_solution(
                  raw.info,
                  Path(fname_trans),
                  Path(fname_src),
                  bem,
                  mindist=20.0,
                  verbose=True,
              )
          log = log.getvalue()
          assert "Total 258/258 points inside the surface" in log
          assert isinstance(fwd, Forward)
          fwds[solver] = fwd
          del fwd
      _compare_forwards(
          fwds["openmeeg"],
          fwds["mne"],
          n_sensors,
          n_sources_kept * 3,
          meg_atol=1,
          eeg_atol=100,
          meg_corr_tol=0.98,
          eeg_corr_tol=0.98,
          meg_rdm_tol=0.1,
          eeg_rdm_tol=0.2,
      )
  
imports: from itertools import product
  from pathlib import Path
  import numpy
  import pytest
  from numpy.testing import assert_allclose, assert_array_equal, assert_array_less
  from mne import convert_forward_solution, create_info, get_volume_labels_from_aseg, make_forward_solution, make_sphere_model, pick_info, pick_types, pick_types_forward, read_cov, read_dipole, read_evokeds, read_forward_solution, read_source_spaces, setup_volume_source_space, write_forward_solution
  from mne._fiff.constants import FIFF
  from mne.bem import make_bem_solution, read_bem_surfaces
  from mne.channels import make_standard_montage
  from mne.datasets import testing
  from mne.dipole import Dipole, fit_dipole
  from mne.forward import Forward, _do_forward_solution, use_coil_def
  from mne.forward._compute_forward import _magnetic_dipole_field_vec
  from mne.forward._make_forward import _create_meg_coils, make_forward_dipole
  from mne.forward.tests.test_forward import assert_forward_allclose
  from mne.io import read_info, read_raw_bti, read_raw_fif, read_raw_kit
  from mne.simulation import simulate_evoked
  from mne.source_estimate import VolSourceEstimate
  from mne.source_space._source_space import _compare_source_spaces, setup_source_space, write_source_spaces
  from mne.surface import _get_ico_surface
  from mne.transforms import Transform
  from mne.utils import catch_logging, requires_mne, requires_mne_mark, requires_openmeeg_mark, run_subprocess
label_desc: Use image node_id 9 for calling a global function with example usage: test_make_forward_solution_openmeeg(n_layers) without return types