code: def test__cache_image():
      image = MagicMock()
      image.save = MagicMock()
      _cache_image(image, "test_image.jpg")
      image.save.assert_called_once()
  
file_path: chitra/tests/image/test_image.py
imports: from unittest.mock import MagicMock
  import numpy
  from PIL import Image
  from chitra.image.image import Chitra, _cache_image
label_desc: Use image node_id 9 for calling a global function with example usage: test__cache_image() without return types