Question from the Elasticsearch test

POST _aliases
{
    "add": "wld-prod",
    "remove": "wld-qa",
     alias": "wld"
}

POST _aliases
{
  "actions": [
    {
        “type”:  "add",
        "index": "wld-prod",
        "alias": "wld"
    },
   {
        "type": “remove”,
        "index": "wld-qa",
        "alias": "wld"
    }
  ]
}

POST _aliases
{
  "actions": [
    {
      "add": {
        "index": "wld-prod",
        "alias": "wld"
      }
    },
   {
      "remove": {
        "index": "wld-qa",
        "alias": "wld"
      }
    }
  ]
}