zipWith

fun <First : Any, Second : Any, Res : Any> Flowable<First>.zipWith(second: Flowable<Second>, zipFun: (First, Second) -> Res): Flowable<Res>

fun <First : Any, Second : Any> Flowable<First>.zipWith(second: Flowable<Second>): Flowable<Pair<First, Second>>

fun <First : Any, Second : Any, Res : Any> Observable<First>.zipWith(second: Observable<Second>, zipFun: (First, Second) -> Res): Observable<Res>

fun <First : Any, Second : Any> Observable<First>.zipWith(second: Observable<Second>): Observable<Pair<First, Second>>