{
  "variants": {
    "": [
      { "model": "block/birch_planks" },
      { "model": "block/birch_planks2" },
      { "model": "block/birch_planks3" },
      { "model": "block/birch_planks4" },
      { "model": "block/birch_planks5" },
      { "model": "block/birch_planks6" }
    ]
  }
}