Method getContexts

/**
 * Returns valid contexts.
 *
 * @return  array
 *
 * @since   4.0.0
 */
public function getContexts() : array
{
    $helper = $this->loadHelper();
    if (!$helper || !\is_callable(array($helper, 'getContexts'))) {
        return [];
    }
    return $helper::getContexts();
}