docs: def _image_width(image):
      """
      Returns the width of the image found at the path supplied by `image`
      relative to your project's images directory.
      """
      if not Image:
          raise Exception("Images manipulation require PIL")
      file = StringValue(image).value
      path = None
      try:
          width = sprite_images[file][0]
      except KeyError:
          width = 0
          if callable(STATIC_ROOT):
              try:
                  _file, _storage = list(STATIC_ROOT(file))[0]
                  path = _storage.open(_file)
              except:
                  pass
          else:
              _path = os.path.join(STATIC_ROOT, file)
              if os.path.exists(_path):
                  path = open(_path, 'rb')
          if path:
              image = Image.open(path)
              size = image.size
              width = size[0]
              sprite_images[file] = size
      return NumberValue(width, 'px')