code: def test_open():
      # Arrange
      TEST_FILE = "Tests/images/hopper.wal"
  
      # Act
      with WalImageFile.open(TEST_FILE) as im:
          # Assert
          assert im.format == "WAL"
          assert im.format_description == "Quake2 Texture"
          assert im.mode == "P"
          assert im.size == (128, 128)
  
          assert isinstance(im, WalImageFile.WalImageFile)
  
          assert_image_equal_tofile(im, "Tests/images/hopper_wal.png")
  
label_desc: Use image node_id 1 for calling a global function with example usage: test_open() without return types