This line https://github.com/Ugdhar/structest/blob/master/src/main/java/ugdhar/mod/structest/BrickHousePiece.java#L47
In newer versions of forge it seems to be mapped correctly, it's public abstract boolean create(IWorld worldIn, ChunkGenerator<?> chunkGeneratorIn, Random randomIn, MutableBoundingBox mutableBoundingBoxIn, ChunkPos chunkPosIn); in the code