How to add HttpClient Interceptors conditionally in Angular -

recently have been using interceptors angular httpclient.

i add headers corresponding http methods , not need headers.

how can tell interceptor conditionally add interceptors methods? can split services 1 service headers , 1 without headers or 1 different headers , 1 different.

ngmodule providers

{   provide: http_interceptors,   useclass: authinterceptor,   multi: true, },{   provide: http_interceptors,   useclass: angularinterceptor,   multi: true, } 

myinterceptors

@injectable() export class authinterceptor implements httpinterceptor {   intercept(req: httprequest<any>, next: httphandler): observable<httpevent<any>> {     const authreq = req.clone({headers: req.headers.set('x-auth-token', "-------------------------")});     return next.handle(authreq);    } }   @injectable() export class angularinterceptor implements httpinterceptor {   intercept(req: httprequest<any>, next: httphandler): observable<httpevent<any>> {     return next.handle(req).do(event => {}, err => {         if(err instanceof httperrorresponse){             console.log("error caught interceptor");             //observable.throw(err);         }     });   } }