Not able to get a new `instance` from a `class` - angular5

Question

Here is my detail class:
export class Details {
model = {
"name":"",
"city":"",
"pin" : ""
}
}
getting a instance for various page :
import {Injectable} from '#angular/core';
import { BehaviorSubject } from 'rxjs';
import { Details } from './details';
#Injectable()
export class SharedDataService {
constructor(){}
object1 = new Details().model; //updates this data to object 2
object2 = new Details().model; //it is not empty, updated with object 1
sharedData = new BehaviorSubject( this.object1 );
sharedObserver = this.sharedData.asObservable();
sharedDataHello = new BehaviorSubject( this.object2 );
sharedObserverHello = this.sharedData.asObservable();
updateSharedData(object){
this.sharedData.next(object);
}
updateSharedDataHello(object){
this.sharedDataHello.next(object);
}
}
In object2 - I am looking for empty object. but the object1 values are assigned to object2 - how to prevent this?
Live demo - navigate to hello page and see the console.

Answer 1

I updated the service as follow it works fine:
import {Injectable} from '#angular/core';
import { BehaviorSubject } from 'rxjs';
import { Details } from './details';
#Injectable()
export class SharedDataService {
object1 = new Details().model;
object2 = new Details().model;
constructor(){
console.log( '1', this.object1);
console.log( '2', this.object2);
}
sharedData = new BehaviorSubject( this.object1 );
sharedObserver = this.sharedData.asObservable();
sharedDataHello = new BehaviorSubject( this.object2 );
sharedObserverHello = this.sharedDataHello.asObservable();
updateSharedData(object){
this.sharedData.next(object);
}
updateSharedDataHello(object){
this.sharedDataHello.next(object);
}
}