minecraft-src/data/minecraft/worldgen/template_pool/trial_chambers/entrance.json

{
  "elements": [
    {
      "element": {
        "element_type": "minecraft:single_pool_element",
        "location": "minecraft:trial_chambers/corridor/addon/display_1",
        "processors": {
          "processors": []
        },
        "projection": "rigid"
      },
      "weight": 1
    },
    {
      "element": {
        "element_type": "minecraft:single_pool_element",
        "location": "minecraft:trial_chambers/corridor/addon/display_2",
        "processors": {
          "processors": []
        },
        "projection": "rigid"
      },
      "weight": 1
    },
    {
      "element": {
        "element_type": "minecraft:single_pool_element",
        "location": "minecraft:trial_chambers/corridor/addon/display_3",
        "processors": {
          "processors": []
        },
        "projection": "rigid"
      },
      "weight": 1
    }
  ],
  "fallback": "minecraft:empty"
}