the key for access
the flag of the deletion was succeed or not
return the value in the cache by the key
the key for access
the value in the cache by the key
return the boolean value whether it have the key or not
the key for access
Whether it have the key or not.
set key and value
the key for access
the value as a cache item
true: succeed to set value, false: not set (already exists)
delete the value