code: private HashMap<String, Object> getAggregationMap(JsonReader in) throws IOException {
      HashMap<String, Object> objMap = new HashMap<>();
      while (in.peek() != JsonToken.END_DOCUMENT) {
        parseNext(in, objMap);
      }
      return objMap;
    }
docs: Converts JSON into a Map representing a {@link QueryAggregation} object.
  
  @param in {@link JsonReader} object used for parsing
  @return Map representing the {@link QueryAggregation} object
  @throws IOException signals that there has been an IO exception