code: def image_url(path, only_path=False, cache_buster=True, dst_color=None, src_color=None, spacing=None, collapse_x=None, collapse_y=None):
      
      return _image_url(path, only_path, cache_buster, dst_color, src_color, False, None, spacing, collapse_x, collapse_y)
docs: Generates a path to an asset found relative to the project's images
      directory.
      Passing a true value as the second argument will cause the only the path to
      be returned instead of a `url()` function