code: private static Object getObjectFromMap(Map map, String key) {
      Utf8 utf8Key = new Utf8(key);
      return map.get(utf8Key);
    }
docs: This method is to get object from map given a key as string.
  Avro persists string as Utf8
  @param map passed from {@link #getFieldHelper(Map, Object, List, int)}
  @param key passed from {@link #getFieldHelper(Map, Object, List, int)}
  @return This could again be a GenericRecord