code: def transform(matches, framework, namespace, static_endpoint):
      
      transformed = []
      namespace = namespace + '/' if namespace else ''
  
      for attribute, elements in matches:
          for element in elements:
              asset_location = get_asset_location(element, attribute)
  
              # string substitution
              sub_dict = {
                  'static_endpoint': static_endpoint, 'namespace': namespace,
                  'asset_location': asset_location
                  }
              transformed_string = frameworks[framework] % sub_dict
  
              res = (attribute, element[attribute], transformed_string)
              transformed.append(res)
  
      return transformed
docs: The actual transformation occurs here.
  
      flask example: images/staticfy.jpg', ==>
          "{{ url_for('static', filename='images/staticfy.jpg') }}"