code: def test_switch_state():
      light = pv.Light()
  
      light.switch_on()
      assert light.on
      light.switch_off()
      assert not light.on
      light.on = False
      assert not light.on
  
file_path: pyvista/tests/plotting/test_lights.py
imports: import numpy
  import pytest
  import vtk
  import pyvista
label_desc: Use image node_id 8 for calling a global function with example usage: test_switch_state() without return types