Associative array of language-specific character transliteration tables.
The outermost array keys are language codes. For each language code key, the value is an array whose keys are Unicode character codes, and whose values are the transliterations of those characters to US-ASCII. This is set up as needed in PHPTransliteration::replace() by calling PHPTransliteration::readLanguageOverrides().
Type: array
protected $languageOverrides = array();