code: def test_p_la():
      im = hopper("RGBA")
      alpha = hopper("L")
      im.putalpha(alpha)
  
      comparable = im.convert("P").convert("LA").getchannel("A")
  
      assert_image_similar(alpha, comparable, 5)
  
imports: from __future__ import annotations
  import pytest
  from PIL import Image
  from .helper import assert_image, assert_image_equal, assert_image_similar, hopper
label_desc: Use image node_id 17 for calling a global function with example usage: test_p_la() without return types