private static void writeInt(@NotNull JsonWriter writer, @NotNull Element problem, @NotNull String elementName) throws IOException {
    try {
      int intValue = Integer.parseInt(problem.getChildText(elementName));
      writer.name(elementName).value(intValue);
    }
    catch (NumberFormatException e) {
      writer.name(elementName).nullValue();
    }
  }
private static void writeInt(@NotNull JsonWriter writer, @NotNull Element problem, @NotNull String elementName)