How to use [cache.count]

The reference page of cache.count has its arguments, constraints and declaration.

This slot works similarly to the [cache.list] slot, except it only returns the number of items. Below is an example of creating a new cache entry, for then to count how many cache items exists in your cache.

cache.set:cache-item-key
   expiration:5
   value:Howdy world
cache.count