docs: private void DrawPrimitive( DrawBlock b, World w ) throws Exception
      {
          XMLBlockState blockType = new XMLBlockState(b.getType(), b.getColour(),  b.getFace(), b.getVariant());
          if (!blockType.isValid())
              throw new Exception("Unrecogised item type: " + b.getType().value());
          BlockPos pos = new BlockPos( b.getX(), b.getY(), b.getZ() );
          clearEntities(w, b.getX(), b.getY(), b.getZ(), b.getX() + 1, b.getY() + 1, b.getZ() + 1);
          setBlockState(w, pos, blockType );
      }