Know more about the rasa-core Agent update_model function

I am looking to update the previously loaded model in the core-agent object . I did a little digging in the file provided by rasa-core, I found a update_model function, but couldn’t find any use case anywhere how to use it efficiently. I tried using it as per the function documentation but it doesn’t work. I am using rasa version 1.4.5 Is there any use case or any POC on how to use it?