flush
Runs all tasks in the task queue.
queue.flush()
Flushes tasks currently in the task queue. When complete, calls the onComplete
callback.
queue.enqueue( console.log, console, [ "say hi" ], {} );
queue.flush();
// console.logs "say hi"
If the queue's tasks are currently
being flushed, new tasks added will be run without needing to call .flush()
again.