protected function getLastKeyPair()
    {
        // Use count, since empty ArrayAccess objects can still return false for `empty`
        if (count($this->storage) < 1) {
            return null;
        }

        foreach ($this->storage as $name => $value) {
            continue;
        }

        $keyPair = [
            $this->prefix . '_name' => $name,
            $this->prefix . '_value' => $value
        ];

        return $keyPair;
    }