POST /myindex/_search
{
  "size": 0,
  "aggs": {
    "constructor": {
      "terms": {
        "field": "anything",
      }
    }
  }
}

{
  "took": 33,
  "timed_out": false,
  "_shards": {
    "total": 1,
    "successful": 1,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": {
      "value": 1,
      "relation": "eq"
    },
    "max_score": null,
    "hits": []
  },
  "aggregations": {
    "constructor": { /*** CAUSES AN ERROR FOR VALID REASON ***/
      "doc_count_error_upper_bound": 0,
      "sum_other_doc_count": 0,
      "buckets": []
    }
  }
}