[Tutorial] Naive throttling for a block from rapid execution for a specific period of time. Inspired by https://rxmarbles.com/#throttleTime

throttle.swift

import Foundation

private var timer: Timer?
func throttle(_ interval: TimeInterval, block: @escaping (() -> Void)) {
    timer?.invalidate()
    timer = Timer.scheduledTimer(withTimeInterval: interval, repeats: false, block: { _ in
        block()
    })
}

How expensive is the Timer creation?
Will it add value if notched up the implementation to make use operation queues?