Unable to append Properties to BlockState

[TheSilkMiner]

Describe the bug

The Block#appendProperties method is never called, which implies that properties cannot be added to the BlockState.
Attempting to use said properties will then result (as expected) in a crash.

To Reproduce

Steps to reproduce the behavior:

1. Create a new Sandbox Addon and create a new subclass of BaseBlock.
2. Override the appendProperties method and attempt to add any property to the builder (in my case builder.add(Properties.CONDITIONAL))
3. Override onBlockPlaced and attempt to set the property specified on the given state (e.g. state.with(Properties.CONDITIONAL, false))
4. Register the block, then run the testing environment.
5. Place a block: Minecraft will crash with an IllegalArgumentException.

Expected behavior

To be able to add properties to the state.

Additional context

Crash Reported produced following the previous procedure: crash-2019-12-30_21.13.27-client.txt
Sandbox version: 0.2.1-SNAPSHOT (API and implementation)