Error TS6138 - Property xxxx is declared but its value is never read

export class AppModule {
  constructor(private s: ActiveCartService){
    if( s === undefined){
      console.log(s);
    }
    s.isStable().subscribe((data) => console.log('isStable: ' , data));
  }
}

 "noUnusedLocals": false,
 "noUnusedParameters": false,