code: def test_volume_draw():
      with TestingCanvas(bgcolor="k", size=(100, 100)) as c:
          v = c.central_widget.add_view()
          v.camera = "turntable"
          v.camera.fov = 70
          # Create
          np.random.seed(2376)
          vol = np.random.normal(size=(20, 20, 20), loc=0.5, scale=0.2)
          vol[8:16, 8:16, :] += 1.0
          scene.visuals.Volume(vol, parent=v.scene)  # noqa
          v.camera.set_range()
          assert_image_approved(c.render(), "visuals/volume.png")
  
imports: import pytest
  import numpy
  from vispy import scene
  from vispy.testing import TestingCanvas, requires_application, run_tests_if_main, requires_pyopengl, raises
  from vispy.testing.image_tester import assert_image_approved, downsample
  from vispy.testing.rendered_array_tester import compare_render, max_for_dtype
label_desc: Use image node_id 3 for calling a global function with example usage: test_volume_draw() without return types