TriggerStream.java

// Return true jika email user sudah terpakai
        Observable<Boolean> emailStream = RxTextView.textChanges(etEmail)
                .map(new Func1<CharSequence, String>() {
                    @Override
                    public String call(CharSequence charSequence) {
                        return charSequence.toString();
                    }
                })
                .filter(new Func1<String, Boolean>() {
                    @Override
                    public Boolean call(String input) {
                        return input.length() > 3;
                    }
                })
                .debounce(100,TimeUnit.MILLISECONDS);