Villagers no longer show the items they want to trade to the player

When you hold the Emerald in your hand, the villagers don't show what they trade.

Steps to Reproduce:

1. Spawn a villager
2. Give the villager a profession
3. Hold an emerald

Observed Results:
The villager does not show what item it wants to trade to the player.

Expected Results:
The villager should show what item it wants to trade to the player.