As the title says, I can't find a proper way to register a block entity type in 1.21.3 as BlockEntityType.Builder class has been made private. I have scoured the internet and even the docs tell me to use this class I don't have access to. What is the preferred way of doing registering the block entity type? For context, I'm in the process of updating my mod from 1.19 to the 1.21.3.