Implements hook_transliteration_overrides_alter().
function transliterate_test_transliteration_overrides_alter(&$overrides, $langcode) {
if ($langcode == 'zz') {
// The default transliteration of Ä is A, but change it to Z for testing.
$overrides[0xc4] = 'Z';
// Also provide transliterations of two 5-byte characters from
// http://en.wikipedia.org/wiki/Gothic_alphabet.
$overrides[0x10330] = 'A';
$overrides[0x10338] = 'Th';
}
}