how to merge map in immutable.js?

I want to get map like below:

Map{
   "status":1,
    "user":{
        "name":"more",
        "age":8,
        "id":1
    }
}

My full code is:

import {fromJS} from 'immutable'
let b={
    "user":{
         name:"more11",
         age:8
    },
    "status":1
}
let d={
    "id":1,
    "name":"more",
    "age":19
}
let d1=fromJS(d)
let b2=fromJS(b)
Const map2=b1.get('user).mergeDeepIn(d1)
console.log(map2.getIn(['user','name']));
console.log(map2.getIn(['user','age']));

Original code image