code: def test_vrt_vsifile(data_dir, path_white_gemini_iv_vrt):
      """Successfully read an in-memory VRT"""
      with open(path_white_gemini_iv_vrt) as vrtfile:
          source = vrtfile.read()
          source = source.replace(
              '<SourceFilename relativeToVRT="1">389225main_sw_1965_1024.jpg</SourceFilename>',
              '<SourceFilename relativeToVRT="0">{}/389225main_sw_1965_1024.jpg</SourceFilename>'.format(
                  data_dir
              ),
          )
          source = BytesIO(source.encode("utf-8"))
  
      with FilePath(source) as vsifile:
          with vsifile.open() as src:
              assert src.driver == "VRT"
              assert src.count == 3
              assert src.dtypes == ("uint8", "uint8", "uint8")
              assert src.read().shape == (3, 768, 1024)
  
imports: from io import BytesIO
  import logging
  import os.path
  import pytest
  import rasterio
  from rasterio.enums import MaskFlags
  from rasterio.shutil import copyfiles
  from rasterio.windows import Window
  import io
label_desc: Use image node_id 15 for calling a global function with example usage: test_vrt_vsifile(data_dir, path_white_gemini_iv_vrt) without return types