withPermitN

import arrow.fx.coroutines.*

suspend fun main(): Unit {
  //sampleStart
  val semaphore = Semaphore(5)
  val available = semaphore.withPermitN(4) {
    println("I'll run after I got 4 permits first")
    semaphore.available()
  }
  //sampleEnd
  println("available: $available")
}