Cancelable Delay Function - Swift 4.0

DelayHelper.swift

class DelayHelper {
  private var cancelled = false
    
    static func run(delay: Double, closure: @escaping () -> ()) {
        DispatchQueue.main.asyncAfter(deadline: .now() + delay) {
            if !self.cancelled {
                closure()
            }
        }
    }
    
    static func cancel() {
        cancelled = true
    }
}