In T98290#1424169, @thiemowmde wrote:

Had a chat with @Bene. This is what's left in Entity and not deprecated:

• Entity::getFingerprint already has an interface, FingerprintProvider. In 3.1, the method should be deprecated in Entity and un-deprecated in Item and Property (via duplicate implementations, similar to Item::setLabel and such).
• Entity::setFingerprint needs investigation. The most flexible solution is to create a FingerprintHolder with a getter and a setter, similar to StatementListHolder, make Item and Property implement this interface and deprecate the methods in Entity. But do we really need setFingerprint? If getFingerprint is guaranteed to not return a copy, all manipulations can be done on the returned Fingerprint object and setFingerprint never needs to be called. What we need to do:
  • Check if all usages of setFingerprint (especially the ones in Deserializers) are optional and can be removed.
  • The guarantee that getFingerprint does not return a copy must be added to the methods documentation.
• Entity::isEmpty should be deprecated and un-deprecated in Item and Property.
• Entity::clear should be deprecated and later die. Just create a new Item if you need a new item. Repurposing existing entities is ugly.
• Entity::copy. Not sure about this. It used a lot, more than 100 times, mostly in tests obviously but also in production. But it's very, very trivial and should be avoided anyway. Better create a new object.