I copied this example from since `publish = multicast(Subject())`.
```Scala
  @Test def exampleWithPublish() {
    val unshared = Observable.from(1 to 4)
    val shared = unshared.publish
    shared.subscribe(n => println(s"subscriber 1 gets $n"))
    shared.subscribe(n => println(s"subscriber 2 gets $n"))
    shared.connect
  }
```