code: def get_value_from_content(key):
      
      def value_from_content_function(service, message):
          """Actual implementation of get_value_from_content function.
  
          :param service: SelenolService object.
          :param message: SelenolMessage request.
          """
          return _get_value(message.content, key)
      return value_from_content_function
docs: Get a value from the path specifed.
  
      :param key: Array that defines the path of the value inside the message.