(PECL memcached >= 2.0.0)
Memcached::deleteMulti — Delete multiple items
$keys, int $time = 0): array
   Delete the array of keys from the server.
  
keysThe keys to be deleted.
timeThe amount of time the server will wait to delete the items.
Note: As of memcached 1.3.0 (released 2009) this feature is no longer supported. Passing a non-zero
timewill cause the deletion to fail. Memcached::getResultCode() will returnMEMCACHED_INVALID_ARGUMENTS.
   Returns an array indexed by keys. Each element
   is true if the corresponding key was deleted, or one of the
   Memcached::RES_* constants if the corresponding deletion
   failed.
   
   The Memcached::getResultCode() will return
   the result code for the last executed delete operation, that is, the delete
   operation for the last element of keys.
  
