  ````
  
  */
-class Countdown: Timer {
+public class Countdown: Timer {
   
   override func tick(every interval: Double, _ update: (Double) -> ()) {
     let interval = interval > 0 ? -interval : interval

 A protocol that groups methods and properties for objects that wants to fire and handle time events.
 
 */
protocol TimerManagerType {
  
  /// The gap between executions in seconds.
  var interval: Double { get }

    }
  }
  
  public func cancel() {
    
    if timer != nil {
      dispatch_source_cancel(timer!)
    }
  }
  
  public func pause() {
    paused = true
  }
}
