I have an angular service provided in root

```
import {Injectable} from "@angular/core";
import {BehaviorSubject} from "rxjs";
import {Admin} from "../models/admin.model";
import {AdminsService} from "./admins.service";

@Injectable({
  providedIn: 'root'
})
export class CurrentUserService {
  public user$: BehaviorSubject<Admin> = new BehaviorSubject(null);

  constructor(private _adminsService: AdminsService) {
    console.log('current user service instantiated');
    this._adminsService.getCurrentUser()
      .subscribe(user => {
        this.user$.next(user);
      });
  }

  public update() {
    this._adminsService.getCurrentUser().subscribe(user => {
      this.user$.next(user);
    })
  }

  public clear() {
    this.user$.next(null);
  }
}

```

I provide it and Http Interceptor in app.module in this way: 

```
providers: [
    CurrentUserService,
    {
      provide: HTTP_INTERCEPTORS,
      useClass: AuthInterceptor,
      multi: true
    }
  ],

```

And when I try to inject it into interceptor i get a lot of messages from constructor, that indicates that service instantiates many times. 
Can anybody explain this behavior and may be have some idea of how to fix it? 

[console with messages screenshot](https://i.stack.imgur.com/tH8oP.png)