core-bundle/src/Resources/contao/library/Contao/ClassLoader.php
public static function addNamespaces($names)
	{
		@trigger_error('Using ClassLoader::addNamespaces() has been deprecated and will no longer work in Contao 5.0.', E_USER_DEPRECATED);

		foreach ($names as $name)
		{
			self::addNamespace($name);
		}
	}
public static function addNamespaces($names)
	{
		@trigger_error('Using ClassLoader::addNamespaces() has been deprecated and will no longer work in Contao 5.0.', E_USER_DEPRECATED);

		foreach ($names as $name)
		{
			self::addNamespace($name);
		}
	}
Add multiple new namespaces

@param array $names An array of namespace names

@deprecated Deprecated since Contao 4.2, to be removed in Contao 5.