queryParamsHandling in Angular 4

–TS File (server.component.ts)

import { Component, OnInit } from '@angular/core';
import { ActivatedRoute, Params, Router } from "@angular/router";

import { ServersService } from '../servers.service';

@Component({
  selector: 'app-server',
  templateUrl: './server.component.html',
  styleUrls: ['./server.component.css']
})
export class ServerComponent implements OnInit {
  server: {id: number, name: string, status: string};

  constructor(private serversService: ServersService,
              private route: ActivatedRoute,
              private router: Router) { }

  ngOnInit() {
    const id = +this.route.snapshot.params['id'];
    this.server = this.serversService.getServer(id);
    this.route.params
      .subscribe(
        (params: Params) => {
          this.server = this.serversService.getServer(+params['id']);          
        }
      )
  }

  onEdit(){
    this.router.navigate(['edit'], {relativeTo: this.route, queryParamsHandling:'preserve'})
  }

}