The utility is designed for convenient redefinition of classes from the vendor by copying them to the overriden directory in the root of the project and adding them to the classmap, which ensures the priority of such classes over their originals in the autoloader. If the overriden directory does not exist, the utility will create it.

Usage:

php vendor/bin/overrider --namespace="Foo\Bar\Baz" [-r, --recursive]

--namespace         Required, accepts the namespace of a class that must already be registered with the autoloader.
-r, --recursive     Optional, generates directories for the overridden class in accordance with the PSR-0.

Make sure you are running the utility from the project root, the composer.json file is available, and the overridden class is already registered in the autoloader.