(PECL memcached >= 2.0.0)
Memcached::touch — Set a new expiration on an item
Memcached::touch() sets a new expiration value on the given key.
keyThe key under which to store the value.
expirationThe expiration time, defaults to 0. See Expiration Times for more info.
Returns true on success or false on failure.
Use Memcached::getResultCode() if necessary.