Method _

/**
 * Class loader method
 *
 * Additional arguments may be supplied and are passed to the sub-class.
 * Additional include paths are also able to be specified for third-party use
 *
 * @param   string  $key         The name of helper method to load, (prefix).(class).function
 *                               prefix and class are optional and can be used to load custom
 *                               html helpers.
 * @param   array   $methodArgs  The arguments to pass forward to the method being called
 *
 * @return  mixed  Result of HTMLHelper::call($function, $args)
 *
 * @since   1.5
 * @throws  \InvalidArgumentException
 */
public static final function _(string $key, ...$methodArgs)
{
    list($key, $prefix, $file, $func) = static::extract($key);
    if (\array_key_exists($key, static::$registry)) {
        $function = static::$registry[$key];
        return static::call($function, $methodArgs);
    }
    /*
     * Support fetching services from the registry if a custom class prefix was not given (a three segment key),
     * the service comes from a class other than this one, and a service has been registered for the file.
     */
    if ($prefix === 'JHtml' && $file !== '' && static::getServiceRegistry()->hasService($file)) {
        $service = static::getServiceRegistry()->getService($file);
        $toCall = array($service, $func);
        if (!\is_callable($toCall)) {
            throw new \InvalidArgumentException(sprintf('%s::%s not found.', $file, $func), 500);
        }
        static::register($key, $toCall);
        return static::call($toCall, $methodArgs);
    }
    $className = $prefix . ucfirst($file);
    if (!class_exists($className)) {
        $path = Path::find(static::$includePaths, strtolower($file) . '.php');
        if (!$path) {
            throw new \InvalidArgumentException(sprintf('%s %s not found.', $prefix, $file), 500);
        }
        \JLoader::register($className, $path);
        if (!class_exists($className)) {
            throw new \InvalidArgumentException(sprintf('%s not found.', $className), 500);
        }
    }
    // If calling a method from this class, do not allow access to internal methods
    if ($className === __CLASS__) {
        if (!(new \ReflectionMethod($className, $func))->isPublic()) {
            throw new \InvalidArgumentException('Access to internal class methods is not allowed.');
        }
    }
    $toCall = array($className, $func);
    if (!\is_callable($toCall)) {
        throw new \InvalidArgumentException(sprintf('%s::%s not found.', $className, $func), 500);
    }
    static::register($key, $toCall);
    return static::call($toCall, $methodArgs);
}