the amount of time in seconds to delay after the first item is enqueued
the amount of time within the delay before the handler is called when no additional items can be added to the queue (they get backlogged within this time period and pushed into the next batch).
the function to deal with the items in the queue after the delay has elapsed.
DelayedQueue allows enqueuing of items that are handled by the handler after a specific delay.
If delay is 5.0 and quietPeriod is 2.0 items can continue to be added for three seconds before reaching the quiet period when items are backlogged.
the type of items this queue accepts