Feature request name
There is no method of getting ILiquidDefinition which corresponds to fluid's blocksates (or this method is not described in mod's documentation). This can be implemented through net.minecraftforge.fluids.FluidRegistry.

Feature request description
I would like to have a method of getting ILiquidDefinition by corresponding IBlock/IBlockState/IBlockDefinition.

Feature request reason
It is useful for making custom tools for working with fluids and to make some fluid container items to behave like buckets.

Feature request dependencies
This feature possibly needs implementing a new ZenClass, which will provide a way to interact with forge's FluidRegistry.