curl --request POST \
  --url https://sync.useparagon.com/api/permissions/{syncId}/expand \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "object": "<string>",
  "relation": "<string>"
}
'

{
  "tree": {
    "root": {
      "name": "<string>",
      "leaf": {
        "users": {
          "users": [
            "<string>"
          ]
        },
        "computed": {
          "userset": "<string>"
        },
        "tupleToUserset": {
          "tupleset": "<string>",
          "computed": [
            {
              "userset": "<string>"
            }
          ]
        }
      },
      "difference": {
        "base": "<unknown>",
        "subtract": "<unknown>"
      },
      "union": {
        "nodes": "<array>"
      },
      "intersection": {
        "nodes": "<array>"
      }
    }
  }
}