export class JwtRefreshInterceptor implements HttpInterceptor {

  public constructor(
    private httpClient: HttpClient,
  ) { }

  intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    return next.handle(request).catch((error: HttpErrorResponse) => {
      if (error.status === 401) {
        return this.httpClient.post(environment.base_uri + 'auth/refresh', {}).flatMap((response) => {
          // get token from response.
          // put token in localstorage.
          // add token to the request.

          // Do the request again with the new token.
          return next.handle(request);
        });
      }

      return Observable.throw(error);
    });
  }
}

Provider parse errors:
Cannot instantiate cyclic dependency! InjectionToken_HTTP_INTERCEPTORS ("[ERROR ->]"): in NgModule AppModule in ./AppModule@-1:-1