{
  "type": "minecraft:random_patch",
  "config": {
    "tries": 32,
    "xz_spread": 5,
    "y_spread": 3,
    "feature": {
      "feature": "minecraft:single_piece_of_grass",
      "placement": [
        {
          "type": "minecraft:heightmap",
          "heightmap": "MOTION_BLOCKING"
        },
        {
          "type": "minecraft:block_predicate_filter",
          "predicate": {
            "type": "minecraft:matching_blocks",
            "blocks": "minecraft:air"
          }
        }
      ]
    }
  }
}