public function close(): bool
	{
		if (isset($this->memcached))
		{
			isset($this->lockKey) && $this->memcached->delete($this->lockKey);

			if (! $this->memcached->quit())
			{
				return false;
			}

			$this->memcached = null;

			return true;
		}

		return false;
	}