code: def extensions_as_elements(self, tag, schema):
          
          result = []
          for ext in self.find_extensions(tag, schema.NAMESPACE):
              ets = schema.ELEMENT_FROM_STRING[tag]
              result.append(ets(ext.to_string()))
          return result
docs: Return extensions that has the given tag and belongs to the
          given schema as native elements of that schema.
  
          :param tag: The tag of the element
          :param schema: Which schema the element should originate from
          :return: a list of native elements