code: def test_add_markers_using_plot_glass_brain():
      """Tests for adding markers through plot_glass_brain."""
      fig = plot_glass_brain(None)
      coords = [(-34, -39, -9)]
      fig.add_markers(coords)
      fig.close()
      # Add a single marker in right hemisphere such that no marker
      # should appear in the left hemisphere when plotting
      display = plot_glass_brain(None, display_mode="lyrz")
      display.add_markers([[20, 20, 20]])
      # Check that Axe 'l' has no marker
      assert display.axes["l"].ax.collections[
          0
      ].get_offsets().data.shape == (
          0,
          2,
      )
      # Check that all other Axes have one marker
      for d in "ryz":
          assert display.axes[d].ax.collections[
              0
          ].get_offsets().data.shape == (
              1,
              2,
          )
      # Add two markers in left hemisphere such that no marker
      # should appear in the right hemisphere when plotting
      display = plot_glass_brain(None, display_mode="lyrz")
      display.add_markers(
          [[-20, 20, 20], [-10, 10, 10]], marker_color=["r", "b"]
      )
      # Check that Axe 'r' has no marker
      assert display.axes["r"].ax.collections[
          0
      ].get_offsets().data.shape == (
          0,
          2,
      )
      # Check that all other Axes have two markers
      for d in "lyz":
          assert display.axes[d].ax.collections[
              0
          ].get_offsets().data.shape == (
              2,
              2,
          )
  
file_path: nilearn/nilearn/plotting/tests/test_img_plotting/test_plot_glass_brain.py
imports: import matplotlib.pyplot
  import numpy
  import pytest
  from nibabel import Nifti1Image
  from nilearn.image import get_data
  from nilearn.plotting import plot_glass_brain
label_desc: Use image node_id 4 for calling a global function with example usage: test_add_markers_using_plot_glass_brain() without return types