fix(fromEvent): Defines toString to fix Closure compilations (#3417)
fix(fromEvent): Defines toString to fix Closure compilations (#3417)


IgorMinar/RxJS,trxcllnt/RxJS,jayphelps/rxjs,ReactiveX/RxJS,trxcllnt/RxJS,kwonoj/RxJS,benlesh/RxJS,ReactiveX/RxJS,Brocco/RxJS,ReactiveX/RxJS,IgorMinar/RxJS,benlesh/RxJS,jayphelps/rxjs,benlesh/RxJS,kwonoj/RxJS,kwonoj/RxJS,martinsik/rxjs,jayphelps/rxjs,trxcllnt/RxJS,martinsik/rxjs,benlesh/RxJS,Brocco/RxJS,ReactiveX/rxjs,ReactiveX/RxJS,jayphelps/rxjs,ReactiveX/rxjs,ReactiveX/rxjs,jayphelps/rxjs,ReactiveX/rxjs,trxcllnt/RxJS,martinsik/rxjs,Brocco/RxJS,Brocco/RxJS,kwonoj/RxJS,martinsik/rxjs