         let popTime             = dispatch_time(DISPATCH_TIME_NOW, delta)
         let queue               = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)
         
-        dispatch_after(popTime, queue) { () -> Void in
+        dispatch_after(popTime, queue) { 
             callback()
         }
     }

        :param: Name of queue
        :param: Block called on background queue.
    */
    public class func executeInBackground(block:()->Void, callback:()->Void) {
        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), { () -> Void in
            block()
            
            dispatch_async(dispatch_get_main_queue(), callback)
        })
    }
    
    /**
        Executes block on the background for provided queue.
    

    public class func executeOnQueue(queue: String, block:()->Void, callback: ()->Void) {
        let dispatchQueue = dispatch_queue_create(queue, DISPATCH_QUEUE_CONCURRENT)
        
        dispatch_async(dispatchQueue) {
            block()

            dispatch_async(dispatch_get_main_queue(), callback)
        }
    }
    
    /**
        Executes block on the background for provided queue.
    
        :param: Name of queue
        :param: Block called on background queue.
        :param: Block called on main thread once background block is complete.
    */
    public class func executeInBackground(block:()->Void, callback:()->Void) {
        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)) {
            block()
            
            dispatch_async(dispatch_get_main_queue(), callback)
        }
    }
    
    /**
