[1.7.10][SOLVED]Block not getting replaced on item right click

[The_Fireplace]

So, I have a code here that should replace cactus with my custom cactus when you right click holding the item:

 

code removed; problem solved

 

I have it in the Item's class, however, when I hold the item and right click a cactus, it doesn't get replaced.

Yes, I have tried without the

code removed; problem solved

section. It still doesn't do it. Anyone know how to make it work?

[shieldbug1]

You're only setting the metadata of the block. Use world.setBlock