v1.4.7/testing/equivalence-tests/tests/nested_set/dynamic_resources.json

{
  "tfcoremock_nested_set": {
    "attributes": {
      "sets": {
        "type": "set",
        "required": true,
        "set": {
          "type": "set",
          "set": {
            "type": "string"
          }
        }
      }
    }
  }
}