Cats Effect Sync demo

SyncDemo.scala

package cats_effect_typeclass_exericise.sync

import java.time.format.DateTimeFormatter
import cats.effect.{ExitCode, IO, IOApp, Sync}
import cats.instances.list._
import cats.syntax.parallel._
import cats.syntax.functor._
import cats.syntax.flatMap._

object Util {
  private val formatter = DateTimeFormatter.ofPattern("mm:ss")

  def putIn(milli: Int, s: Any): String = {
    Thread.sleep(milli)
    val threadId      = Thread.currentThread.getId
    val currentMinSec = java.time.LocalTime.now.format(formatter)
    println(s"in thread($threadId) at $currentMinSec): $s")
    s.toString
  }
  def putLine(s: Any):   String = putIn(1000, s)
  def putIn1Sec(s: Any): String = putIn(1000, s)
  def putNow(s: Any):    String = putIn(0,    s)
  def putRnd(s: Any):    String = putIn((math.random * 1000 + 500).toInt, s)
}
import Util._

object SyncDemo extends IOApp {
  override def run(args: List[String]): IO[ExitCode] = {
    val ioa = Sync[IO].delay {
      putNow("A begins")
      putIn1Sec("A ends")
    }
    val iob = Sync[IO].suspend {
      IO {
        putNow("B begins")
        putIn1Sec("B ends")
      }
    }
    putNow("ioa and iob initialized.")
    List(ioa, iob).parSequence.void >> IO(ExitCode.Success)
  }
  //  in thread(1) at 18:37): ioa and iob initialized.
  //  in thread(11) at 18:37): A begins
  //  in thread(12) at 18:37): B begins
  //  in thread(11) at 18:38): A ends
  //  in thread(12) at 18:38): B ends
  //
  //  Process finished with exit code 0
}