Function load_entity_recursive 

pub(crate) fn load_entity_recursive(
    world: &Arc<World>,
    nbt: &BaseNbtCompound<'_>,
    reason: EntitySpawnReason,
    post_load: impl Fn(&SharedEntity),
) -> Option<LoadedEntity>

Loads a complete entity tree from vanilla entity NBT without publishing it to the world. The caller owns the atomic insertion boundary.