code: def test_interface():
      im = Image.new("RGBA", (1, 1), (1, 2, 3, 0))
      assert im.getpixel((0, 0)) == (1, 2, 3, 0)
  
      im = Image.new("RGBA", (1, 1), (1, 2, 3))
      assert im.getpixel((0, 0)) == (1, 2, 3, 255)
  
      im.putalpha(Image.new("L", im.size, 4))
      assert im.getpixel((0, 0)) == (1, 2, 3, 4)
  
      im.putalpha(5)
      assert im.getpixel((0, 0)) == (1, 2, 3, 5)
  
imports: from __future__ import annotations
  from PIL import Image
label_desc: Use image node_id 1 for calling a global function with example usage: test_interface() without return types