language_handle, _build_language_handle
Holds a Locale::Maketext language handle
The builder for this attribute gets the Locale::Maketext language handle from the environment variable $ENV{LANGUAGE_HANDLE}, or creates a default language handler using HTML::FormHandler::I18N. The language handle is used in the field's add_error method to allow localizing.
If you do not set the language_handle, then Locale::Maketext and/or I18N::LangTags may guess, with unexpected results.