TESTIFICATE Villagers

Bring back villagers named TESTIFICATE from Minecraft Beta to most recent versions of Minecraft. These were the first villagers in Minecraft, which were useless because they couldn't trade and weren't intelligent.
To obtain these villagers, you'll need to rename them TESTIFICATE.
When you give this name to a villager, you'll see that its behavior will change:

• It will stop wanting to trade, even if it has a profession, just like in Minecraft Beta.
• It will have special particles that indicate it's an abnormal villager.
• The villager will become dumb and stop moving, as if it had no intelligence, but it actually does.

Renaming the villager to any other name will return it to its normal state, but you won't be able to trade with that villager anymore.