Enforcing entity loader. All loads through this loader are guaranteed to be the values of successful results (or null for some loader methods), and will throw otherwise.
Authorization-result-based entity loader. All loads through this loader are results (or null for some loader methods), where an unsuccessful result means an authorization error or entity construction error occurred. Other errors are thrown.
The primary interface for loading entities. All normal loads are batched, cached, and authorized against the entity's EntityPrivacyPolicy.