code: def test_standard_montages_on_sphere(kind, tol, head_size):
      """Test some standard montage are on sphere."""
      kwargs = dict()
      if head_size != HEAD_SIZE_DEFAULT:
          kwargs["head_size"] = head_size
      montage = make_standard_montage(kind, **kwargs)
      eeg_loc = np.array([ch["r"] for ch in _get_dig_eeg(montage.dig)])
  
      assert_allclose(
          actual=np.linalg.norm(eeg_loc, axis=1),
          desired=np.full((eeg_loc.shape[0],), head_size),
          atol=tol,
      )
  
file_path: mne-python/mne/channels/tests/test_standard_montage.py
imports: import numpy
  import pytest
  from numpy.testing import assert_allclose, assert_array_almost_equal, assert_raises
  from mne import create_info
  from mne._fiff._digitization import _get_dig_eeg, _get_fid_coords
  from mne._fiff.constants import FIFF
  from mne.channels import compute_native_head_t, make_standard_montage
  from mne.channels.montage import HEAD_SIZE_DEFAULT, get_builtin_montages
  from mne.io import RawArray
  from mne.preprocessing.nirs import beer_lambert_law, optical_density
  from mne.transforms import _angle_between_quats, _get_trans, rot_to_quat
label_desc: Use image node_id 3 for calling a global function with example usage: test_standard_montages_on_sphere(kind, tol, head_size) without return types