title: Read Cache Storage Size with Flutter_Cache_Manager
body: <p>I'm using <a href="https://pub.dev/packages/flutter_cache_manager" rel="nofollow noreferrer">Flutter_Cache_Manager</a> Plugin to cache Files in my App.
  Inside the App I want to display the entire Cache-Size in MB but I could not find a solution for that yet.</p>
  <p>Does anyone know how I can read the cache size in MB?</p>
  <p>Thanks</p>