code: def test_lcmv_ctf_comp():
      """Test interpolation with compensated CTF data."""
      raw = mne.io.read_raw_ctf(ctf_fname, preload=True)
      raw.pick(raw.ch_names[:70])
  
      events = mne.make_fixed_length_events(raw, duration=0.2)[:2]
      epochs = mne.Epochs(raw, events, tmin=-0.1, tmax=0.2)
      evoked = epochs.average()
  
      data_cov = mne.compute_covariance(epochs)
      fwd = mne.make_forward_solution(
          evoked.info,
          None,
          mne.setup_volume_source_space(pos=30.0),
          mne.make_sphere_model(),
      )
      with pytest.raises(ValueError, match="reduce_rank"):
          make_lcmv(evoked.info, fwd, data_cov)
      filters = make_lcmv(evoked.info, fwd, data_cov, reduce_rank=True)
      assert "weights" in filters
  
      # test whether different compensations throw error
      info_comp = evoked.info.copy()
      set_current_comp(info_comp, 1)
      with pytest.raises(
          RuntimeError, match="Compensation grade .* not match"
      ):
          make_lcmv(info_comp, fwd, data_cov)
  
imports: from contextlib import nullcontext
  from copy import deepcopy
  from inspect import signature
  import numpy
  import pytest
  from numpy.testing import assert_allclose, assert_array_almost_equal, assert_array_equal, assert_array_less
  from scipy import linalg
  from scipy.spatial.distance import cdist
  import mne
  from mne import EvokedArray, VolSourceEstimate, VolVectorSourceEstimate, compute_rank, convert_forward_solution, pick_channels_cov, read_forward_solution, read_vectorview_selection
  from mne._fiff.compensator import set_current_comp
  from mne._fiff.constants import FIFF
  from mne.beamformer import Beamformer, apply_lcmv, apply_lcmv_cov, apply_lcmv_epochs, apply_lcmv_raw, make_dics, make_lcmv, read_beamformer
  from mne.beamformer._compute_beamformer import _prepare_beamformer_input
  from mne.datasets import testing
  from mne.minimum_norm import apply_inverse, make_inverse_operator
  from mne.minimum_norm.tests.test_inverse import _assert_free_ori_match
  from mne.simulation import simulate_evoked
  from mne.transforms import apply_trans, invert_transform
  from mne.utils import _record_warnings, catch_logging, object_diff
label_desc: Use image node_id 7 for calling a global function with example usage: test_lcmv_ctf_comp() without return types