Large memory usage?

Take the given test:

```php
$usage = memory()[1];

$provider = new \Yethee\Tiktoken\EncoderProvider;
$provider->setVocabCache(storage_path('app'));
$encoder = $provider->getForModel('gpt-4o-mini');

dd(memory()[1]-$usage); // 26mb! 
```

26mb seems a bit much no? Especially considering the cached vocab is only `3.6mb`.