{
  "feature": "minecraft:moss_patch_ceiling",
  "placement": [
    {
      "type": "minecraft:count",
      "count": 30
    },
    {
      "type": "minecraft:in_square"
    },
    {
      "type": "minecraft:height_range",
      "height": {
        "type": "minecraft:uniform",
        "max_inclusive": {
          "absolute": 256
        },
        "min_inclusive": {
          "above_bottom": 0
        }
      }
    },
    {
      "type": "minecraft:environment_scan",
      "allowed_search_condition": {
        "type": "minecraft:matching_blocks",
        "blocks": "minecraft:air"
      },
      "direction_of_search": "up",
      "max_steps": 12,
      "target_condition": {
        "type": "minecraft:solid"
      }
    },
    {
      "type": "minecraft:random_offset",
      "xz_spread": 0,
      "y_spread": -1
    },
    {
      "type": "minecraft:biome"
    }
  ]
}