interceptor angular

por jesuscuesta el en 
import { Injectable } from '@angular/core';
import { HttpInterceptor, HttpRequest, HttpHandler, HttpEvent } from '@angular/common/http';
import { Observable } from 'rxjs';

@Injectable()
export class AuthInterceptor implements HttpInterceptor {
  intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    // Clone the request and set the new header in one step.
    const authReq = req.clone({headers: req.headers.set('Authorization', 'my-auth-token')});

    // send the newly created request
    return next.handle(authReq);
  }
}