DispatchSourceTimer and Swift 3.0
<p>I can't figure out how to make dispatch timer work repeatedly in Swift 3.0. My code:</p>

<pre><code>let queue = DispatchQueue(label: "com.firm.app.timer",
                          attributes: DispatchQueue.Attributes.concurrent)
let timer = DispatchSource.makeTimerSource(flags: DispatchSource.TimerFlags(rawValue: UInt(0)),
                                           queue: queue)

timer.scheduleRepeating(deadline: DispatchTime.now(),
                        interval: .seconds(5),
                        leeway: .seconds(1)
)

timer.setEventHandler(handler: {
     //a bunch of code here
})

timer.resume()
</code></pre>

<p>Timer just fires one time and doesn't repeat itself like it should be. How can I fix this?</p>