Minecraft - Java | Make Villager immobile?

I'm currently programming a Minecraft plugin for version 1.8.8.

Now I have had a Villager spawn by command with slowness so that it can't move.

However, players can still push it away by sneaking and running against the Villager.

Does anyone know how I can prevent this?

I don't know exactly what you want to do but with invisibility blocks I would install the villager and leave a 1 × 1 hole

Entity.setAI (false);