code: def test_brain_linkviewer(renderer_interactive_pyvistaqt, brain_gc):
      """Test _LinkViewer primitives."""
      brain1 = _create_testing_brain(hemi="lh", show_traces=False)
      brain2 = _create_testing_brain(hemi="lh", show_traces="separate")
      brain1._times = brain1._times * 2
      with pytest.warns(RuntimeWarning, match="linking time"):
          _LinkViewer(
              [brain1, brain2],
              time=True,
              camera=False,
              colorbar=False,
              picking=False,
          )
      brain1.close()
  
      brain_data = _create_testing_brain(
          hemi="split", show_traces="vertex"
      )
      link_viewer = _LinkViewer(
          [brain2, brain_data],
          time=True,
          camera=True,
          colorbar=True,
          picking=True,
      )
      link_viewer.leader.set_time(1)
      link_viewer.leader.set_time_point(0)
      link_viewer.leader.update_lut(fmin=0, fmid=0.5, fmax=1)
      link_viewer.leader.set_playback_speed(0.1)
      link_viewer.leader.toggle_playback()
      ui_events.publish(
          link_viewer.leader, ui_events.TimeChange(time=0)
      )
      brain2.close()
      brain_data.close()
  
imports: import os
  import platform
  from pathlib import Path
  from shutil import copyfile
  import numpy
  import pytest
  from matplotlib import image
  from matplotlib.lines import Line2D
  from numpy.testing import assert_allclose, assert_array_equal
  from mne import Dipole, MixedSourceEstimate, SourceEstimate, VolSourceEstimate, create_info, pick_types_forward, read_cov, read_evokeds, read_forward_solution, read_source_estimate, vertex_to_mni, write_surface
  from mne.channels import make_dig_montage
  from mne.datasets import testing
  from mne.io import read_info
  from mne.label import read_label
  from mne.minimum_norm import apply_inverse, make_inverse_operator
  from mne.source_estimate import _BaseSourceEstimate
  from mne.source_space import read_source_spaces, setup_volume_source_space
  from mne.utils import check_version
  from mne.viz import ui_events
  from mne.viz._brain import Brain, _BrainScraper, _LayeredMesh, _LinkViewer
  from mne.viz._brain.colormap import calculate_lut
  from mne.viz.utils import _get_cmap
label_desc: Use image node_id 17 for calling a global function with example usage: test_brain_linkviewer(renderer_interactive_pyvistaqt, brain_gc) without return types