API page: https://api.drupal.org/api/drupal/core!lib!Drupal!Core!Entity!EntityType...
> Creates a new handler instance for a entity type and handler type.
That's not true. It caches the instantiated handlers and only creates one if needed.
Rather than say 'creates', the documentation should explicitly state that handlers are per entity type, not per entity.
This is so developers know that they may statically cache something in handler, but also to ensure the cache is per entity if necessary.
