Extract a value out of the entry's value.

Remove this entry from the cache if it is present in the cache.

Store the value corresponding to this entry.

Update the entry's value.

Determine whether or not the entry existed before the start of the mutating operation that is being evaluated by the trigger.

Determine if this entry exists in the cache.

Get the value that existed before the start of the mutating operation that is being evaluated by the trigger.