Optional ReadonlycapacityCapcity limit
Optional ReadonlydiscardDefault is additions, meaning new items are discarded.
older: Removes items front of the queue (ie older items are discarded)
newer: Remove from rear of queue to make space for new items (ie newer items are discarded)
additions: Only adds new items that there are room for (ie. brand new items are discarded)
Optional Readonlyeq
Queue options.
Example: Cap size to 5 items, throwing away newest items already in queue.