"class" property propagated to the request

[snowindy]

Hello,

When sending post data like this

def resp = rest.post(url){
    auth login, password
    contentType "application/json"
    json {
        user
    }
}

I see that the output contains "class" property.
{"class":"org.icc.callrz.BusinessCard.BusinessCard", ...

I think this should be optional, can you please add a setting to disable this property propagation?