Avatica fetch does not return an update row-count for upsert, delete

request: {
  "request": "prepare",
  "connectionId": "c28224cd-a688-4117-af44-0d1510918bd8",
  "sql": "upsert into test.integer_table values ('test3', ?)",
  "maxRowCount": -1
}

{
  "response": "prepare",
  "statement": {
    "connectionId": "36acc5c4-0136-874a-2fcf-a3ec747d7FD4",
    "id": 1532322378,
    "signature": {
      "columns": [
        
      ],
      "sql": "upsert into test.integer_table values ('test3', ?)",
      "parameters": [
        {
          "signed": false,
          "precision": 0,
          "scale": 0,
          "parameterType": 4,
          "typeName": "INTEGER",
          "className": "java.lang.Integer",
          "name": "?1"
        }
      ],
      "cursorFactory": {
        "style": "LIST",
        "clazz": null,
        "fieldNames": null
      }
    }
  }
}

request: {
  "request": "fetch",
  "connectionId": "36acc5c4-0136-874a-2fcf-a3ec747d7FD4",
  "statementId": 1532322378,
  "parameterValues": [
    {
      "type": "INTEGER",
      "value": 1
    }
  ],
  "offset": 0,
  "fetchMaxRowCount": 100
}

{
  "response": "fetch",
  "frame": {
    "offset": 0,
    "done": true,
    "rows": [
      
    ]
  }
}