minecraft-src/data/minecraft/worldgen/configured_feature/warm_ocean_vegetation.json

{
  "type": "minecraft:simple_random_selector",
  "config": {
    "features": [
      {
        "feature": {
          "type": "minecraft:coral_tree",
          "config": {}
        },
        "placement": []
      },
      {
        "feature": {
          "type": "minecraft:coral_claw",
          "config": {}
        },
        "placement": []
      },
      {
        "feature": {
          "type": "minecraft:coral_mushroom",
          "config": {}
        },
        "placement": []
      }
    ]
  }
}