Megamiun

showThreads = true
val clientIO = Schedulers.newParallel("client-io", 2)
val serverIO = Schedulers.newParallel("server-io", 2)
val serverMain = Schedulers.newParallel("server-main", 2)

fun ioFetchUserById(id: Int) =
    Mono.defer { fetchUserById(id) }
        .delayElement(Duration.of(400, MILLIS))
        .subscribeOn(serverIO)

Megamiun

package br.com.gabryel.playground.rx

import io.reactivex.Observable
import io.reactivex.rxkotlin.toObservable
import io.reactivex.rxkotlin.zipWith
import java.time.LocalTime
import java.util.concurrent.TimeUnit
import kotlin.math.pow

fun main() {

Megamiun

// Inferência de Tipo
val clearlyAString = ""

fun thisFunctionClearlyReturnsANumber(first: Int, second: Int) = first + second

fun thisReturnsNumberOfCharactersOnString(possibleString: Any)?: Int {
    if (possibleString !is String) {
        return IllegalStateException()
    
    // Agora o código sabe que possibleString é sem sombra de dúvida uma String

Megamiun

class PersonalInfo(val phone: String?)

class Person(val personalInfo: PersonalInfo?)

Megamiun

// It seems that a Delegate Class always forwards to the same instance that it was created with. 
// But it opens a possible misunderstanding: If I declare the delegated instance in the constructor 
// as a var, shouldn't it change behaviour when the var changes? Or shouldn't a delegated instance 
// always be a val, so it can't be changed? I think I prefer the first, as it would give the user more choice.

// General Interface
interface Context {
    fun print(printable: String)
}