code: def test_color_mask_L(self, mode):
      im = getattr(self, "gradient_" + mode).copy()
      color = "white"
  
      self.assert_9points_paste(
          im,
          color,
          self.mask_L,
          [
              (127, 191, 254, 191),
              (111, 207, 206, 110),
              (127, 254, 127, 0),
              (207, 207, 239, 239),
              (191, 191, 190, 191),
              (207, 206, 111, 112),
              (254, 254, 254, 255),
              (239, 206, 206, 238),
              (254, 191, 127, 191),
          ],
      )
  
imports: from __future__ import annotations
  import pytest
  from PIL import Image
  from .helper import CachedProperty, assert_image_equal
label_desc: Use image node_id 18 for calling the TestImagingPaste obj's underlying member method code with example usage: obj.test_color_mask_L(mode) without return types