Featuring a topic in Khoros Classic

Hi all,

I'm looking for a way to be able to feature a give topic via the REST API v2. 

I tried doing this in a test endpoint, 

<#assign feature_call = restBuilder()
                    .method("PUT")
                    .path("/messages/11577")
                    .body({
                        "data": {
                            "type": "message",
                            "conversation": {
                                "featured": true
                            }
                        }
                    })
                    .admin(true) />

but it fails with the following error:

{
    "status":"error",
    "message":"The following parameters, or the value passed in for them, are not valid: [featured].",
    "data":{
        "type":"error_data",
        "code":404,
        "developer_message":"The parameter featured is not allowed in an 'update' call.",
        "more_info":""
     },
     "metadata":{}
}

I couldn't find anything in the REST API v1 either. Is there no way to actually feature a message via the API?