code: def test_sanity_dxt1():
      """Check DXT1 images can be opened"""
      with Image.open(TEST_FILE_DXT1.replace(".dds", ".png")) as target:
          target = target.convert("RGBA")
      with Image.open(TEST_FILE_DXT1) as im:
          im.load()
  
          assert im.format == "DDS"
          assert im.mode == "RGBA"
          assert im.size == (256, 256)
  
          assert_image_equal(im, target)
  
imports: from io import BytesIO
  import pytest
  from PIL import DdsImagePlugin, Image
  from .helper import assert_image_equal, assert_image_equal_tofile, hopper
label_desc: Use image node_id 1 for calling a global function with example usage: test_sanity_dxt1() without return types