code: def test_calculate_head_pos_kit():
      """Test calculation of head position using KIT data."""
      raw = read_raw_kit(con_fname, mrk_fname, elp_fname, hsp_fname)
      assert len(raw.info["hpi_results"]) == 1
      chpi_locs = extract_chpi_locs_kit(raw)
      assert chpi_locs["rrs"].shape == (2, 5, 3)
      assert_array_less(chpi_locs["gofs"], 1.0)
      assert_array_less(0.98, chpi_locs["gofs"])
      quats = compute_head_pos(raw.info, chpi_locs)
      assert quats.shape == (2, 10)
      # plotting works
      plot_head_positions(quats, info=raw.info)
      raw_berlin = read_raw_kit(berlin_fname)
      assert_allclose(raw_berlin.info["dev_head_t"]["trans"], np.eye(4))
      assert len(raw_berlin.info["hpi_results"]) == 0
      with pytest.raises(ValueError, match="Invalid value"):
          extract_chpi_locs_kit(raw_berlin)
      with pytest.raises(RuntimeError, match="not find appropriate"):
          extract_chpi_locs_kit(raw_berlin, "STI 014")
      with pytest.raises(RuntimeError, match="no initial cHPI"):
          compute_head_pos(raw_berlin.info, chpi_locs)
  
imports: from pathlib import Path
  import numpy
  import pytest
  from numpy.testing import assert_allclose, assert_array_equal, assert_array_less
  from scipy.interpolate import interp1d
  from scipy.spatial.distance import cdist
  from mne import pick_info, pick_types
  from mne._fiff.constants import FIFF
  from mne.chpi import _chpi_locs_to_times_dig, _compute_good_distances, _get_hpi_initial_fit, _setup_ext_proj, compute_chpi_amplitudes, compute_chpi_locs, compute_chpi_snr, compute_head_pos, extract_chpi_locs_ctf, extract_chpi_locs_kit, filter_chpi, get_active_chpi, get_chpi_info, head_pos_to_trans_rot_t, read_head_pos, write_head_pos
  from mne.datasets import testing
  from mne.forward._compute_forward import _MAG_FACTOR
  from mne.io import RawArray, read_info, read_raw_artemis123, read_raw_ctf, read_raw_fif, read_raw_kit
  from mne.simulation import add_chpi
  from mne.transforms import _angle_between_quats, rot_to_quat
  from mne.utils import assert_meg_snr, catch_logging, object_diff, verbose
  from mne.viz import plot_head_positions
label_desc: Use image node_id 22 for calling a global function with example usage: test_calculate_head_pos_kit() without return types