Admin Menus (question on an example from the codex)

mt = menu test, and the _e() function:

/**
* Displays the returned translated text from translate().
*
* @see translate() Echos returned translate() string
* @since 1.2.0
*
* @param string $text Text to translate
* @param string $domain Optional. Domain to retrieve the translated text
*/
function _e($text, $domain = ‘default’) {
echo translate($text, $domain);
}