isLoginSuccessful
observeOn(scheduler.ui()).subscribeOn(scheduler.io())
.subscribe { isLoginSuccess ->
    if (isLoginSuccess) finishOk()
    else setValidationStateView()
}
.addTo(disposeBag)

unknownEnvironment.rx { it->
    print(it)

}

fun <T> Observable<T>.rx(predicate: () -> (Unit) = {}) {

    this.drivePredicateOnUI()
        .subscribe {
            predicate()
        }.inject()
}

fun <T> Observable<T>.drivePredicateOnUI(scheduler: BaseSchedulerProvider = SchedulerProvider()): Observable<T> = observeOn(scheduler.ui()).subscribeOn(scheduler.io())

fun Disposable.inject() {
    val disposeBag = CompositeDisposable()
    this.addTo(disposeBag)
}

usually we have in any class or in a super class :     val disposeBag = CompositeDisposable()

   override fun onDestroy() {

        super.onDestroy()
        disposeBag.clear()
    }

Type mismatch.
Required:
() → Unit
Found:
(Any?) → Unit
Overload resolution ambiguity. All these functions match.
public inline fun print(message: Any?): Unit defined in kotlin.io
public inline fun print(message: Boolean): Unit defined in kotlin.io
public inline fun print(message: Byte): Unit defined in kotlin.io
public inline fun print(message: Char): Unit defined in kotlin.io
public inline fun print(message: CharArray): Unit defined in kotlin.io
public inline fun print(message: Double): Unit defined in kotlin.io
public inline fun print(message: Float): Unit defined in kotlin.io
public inline fun print(message: Int): Unit defined in kotlin.io
public inline fun print(message: Long): Unit defined in kotlin.io
...

 @CheckReturnValue
    @SchedulerSupport(SchedulerSupport.NONE)
    public final Disposable subscribe(Consumer<? super T> onNext) {
        return subscribe(onNext, Functions.ON_ERROR_MISSING, Functions.EMPTY_ACTION, Functions.emptyConsumer());
    }

fun <T> Observable<T>.rx(
    disposeBag: CompositeDisposable = CompositeDisposable(),
    predicate: (T) -> Unit
) {

    this.driveOnUI()
        .subscribe {
            predicate()
        }.inject(disposeBag)
}

 unknownEnvironment.rx(disposeBag) { it->//passing disposeBag from superclass
                isEnvironmentUnknown.onNext(true)
                validate()
            }