# An example from group member agent
def group_member(ch, method, properties, body):
    """
    Properties:
      correlation_id (str): The UUID for the request.
      reply_to       (str): The RabbitMQ queue name for reply to send to.

    Message(body):
      username    (str): The user to be added/removed from groups.
      groups     (dict): A dictionary with `add` or `remove` key.
        add      (list): A list of groups to be added for the user.
        remove   (list): A list of groups to be removed for the user.
      executed_by (str): The user who request the change.
      host        (str): Hostname where the request comes from.
      interface   (str): whether it's from CLI or WebUI.

    Returns:
      status (bool): Whether or not the operation executed successfully.
      errmsg  (str): Detailed error message if operation failed.
      task    (str): The task name of the agent who handle the message.
    """