code: def test_l():
      # Created with ImageMagick
      # convert hopper.ppm -monochrome -compress None sgi:hopper.bw
      test_file = "Tests/images/hopper.bw"
  
      with Image.open(test_file) as im:
          assert_image_similar(im, hopper("L"), 2)
          assert im.get_format_mimetype() == "image/sgi"
  
file_path: pillow/Tests/test_file_sgi.py
imports: from __future__ import annotations
  import pytest
  from PIL import Image, SgiImagePlugin
  from .helper import assert_image_equal, assert_image_equal_tofile, assert_image_similar, hopper
label_desc: Use image node_id 3 for calling a global function with example usage: test_l() without return types