This plugin can be used in a workbox-strategy to regularly enforce a
limit on the age and / or the number of cached requests.
It can only be used with workbox-strategy instances that have a
custom cacheName property set.
In other words, it can't be used to expire entries in strategy that uses the
default runtime cache name.
Whenever a cached request is used or updated, this plugin will look
at the associated cache and remove any old or extra requests.
When using maxAgeSeconds, requests may be used once after expiring
because the expiration clean up will not have occurred until after the
cached request has been used. If the request has a "Date" header, then
a light weight expiration check is performed and the request will not be
When using maxEntries, the entry least-recently requested will be removed
from the cache first.