19w41a first pass

src/main/java/carpet/fakes/BiomeArrayInterface.java

@@ -0,0 +1,10 @@
+package carpet.fakes;
+
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.world.World;
+import net.minecraft.world.biome.Biome;
+
+public interface BiomeArrayInterface
+{
+    void setBiomeAtIndex(BlockPos pos, World world, Biome what);
+}