def asset_data_uri(path)
      asset = depend_on_asset(path)
      if asset.content_type == 'image/svg+xml'
        svg_asset_data_uri(asset)
      else
        base64_asset_data_uri(asset)
      end
    end
def asset_data_uri(path)
      asset = depend_on_asset(path)
      if asset.content_type == 'image/svg+xml'
        svg_asset_data_uri(asset)
      else
        base64_asset_data_uri(asset)
      end
    end
Returns a `data:` URI with the contents of the asset at the specified
 path, and marks that path as a dependency of the current file.

 Uses URI encoding for SVG files, base64 encoding for all the other files.

 Use `asset_data_uri` from ERB with CSS or JavaScript assets:

     #logo { background: url(<%= asset_data_uri 'logo.png' %>) }

     $('<img>').attr('src', '<%= asset_data_uri 'avatar.jpg' %>')