Inventory.contains() always returning false?

Plugins Plugin Development
1

Is there something really obvious I’m missing here? I simply have:

player.getInventory().contains(ItemTypes.STONE_BUTTON)

I know 100% that I have a stone button in my inventory, so how can this possibly return false?

2

Update your sponge to the experimental release please. It fixes like all the issues your complaining about.

3

Well, if that’s the case whatever plugin he’s making won’t work on the recommended builds?

4

… yes, that’s generally what happens when you use an experimental build