LeoCTH

I'm trying to make a fluid, the bucket was okay, but when you pick it up with bucket, it's turns to a water bucket. Then I try to listen to FillBucketEvent, and using event's result to do the custom bucket. But, I found FluidContainerRegistry.fillFluidContainer(); is not there, even FluidContainerRegistry is not exist. The changelog is not mentioned the class is removed. So I wonder how to solve it.