public DateFormat::getTranslationElement(LanguageInterface $translation_language, $source_config, $translation_config)
Returns the translation form element for a given configuration definition.
For complex data structures (such as mappings) that are translatable wholesale but contain non-translatable properties, the form element is responsible for checking access to the source value of those properties. In case of formatted text, for example, access to the source text format must be checked. If