As a result of EZP-30394 the persistence handler methods: \eZ\Publish\Core\Persistence\Legacy\User\Handler::create and \eZ\Publish\Core\Persistence\Legacy\User\Handler::update should be dropped (on the interface). The only reason for their existence is persistence cache layer which provides cache invalidation.

This requires creating cache invalidation layer for either just User Storage or for Field Type Storage in general. We need to decide and specify how we want to approach this.