      
      - SeeAlso: dispatch_get_global_queue
     */
-    class func userInteractiveQueue() -> dispatch_queue_t {
+    static func userInteractiveQueue() -> dispatch_queue_t {
         return dispatch_get_global_queue(QOS_CLASS_USER_INTERACTIVE, 0)
     }
 


     - SeeAlso: dispatch_get_global_queue
     */
    class func backgroundQueue() -> dispatch_queue_t {
        return dispatch_get_global_queue(QOS_CLASS_BACKGROUND, 0)
    }
}


     - SeeAlso: dispatch_get_global_queue
     */
    static func userInitiatedQueue() -> dispatch_queue_t {
        return dispatch_get_global_queue(QOS_CLASS_USER_INITIATED, 0)
    }

