code: def add_unique_template_variables(self, options):
          
          options.update(dict(
              tiles_url=self.tiles_url,
              tiles_size=self.tiles_size,
              tiles_minzoom=self.tiles_minzoom,
              tiles_maxzoom=self.tiles_maxzoom,
              tiles_bounds=self.tiles_bounds if self.tiles_bounds else 'undefined'))
docs: Update map template variables specific to a raster visual