Add translations for new language.
string $langcode: The langcode of the language.
protected function loadLanguage($langcode) {
// This class is usually a base class but we do not declare as abstract
// because it can be used on its own, by passing a simple array on the
// constructor. This can be useful while testing, but it does not support
// loading specific languages. All available languages should be passed
// in the constructor array.
return array();
}