addTitle method
Implementation
void addTitle(String text,
{String language = 'en', TextEncoding encoding = TextEncoding.UTF8}) {
_titleRecords
.add(TextRecord(language: language, text: text, encoding: encoding));
if (_titleLanguages.contains(language)) {
throw ArgumentError(
"Language of titles can not be repeated, got $language");
}
_titleLanguages.add(language);
}