Override the behavior of title(). Get the name of the vocabulary..
Overrides String::title
function title() {
$query = db_select('taxonomy_vocabulary', 'v');
$query
->addField('v', 'name');
$query
->condition('v.machine_name', $this->argument);
$title = $query
->execute()
->fetchField();
if (empty($title)) {
return t('No vocabulary');
}
return check_plain($title);
}