processFormTypeGuessers example

    public function process(ContainerBuilder $container)
    {
        if (!$container->hasDefinition('form.extension')) {
            return;
        }

        $definition = $container->getDefinition('form.extension');
        $definition->replaceArgument(0, $this->processFormTypes($container));
        $definition->replaceArgument(1, $this->processFormTypeExtensions($container));
        $definition->replaceArgument(2, $this->processFormTypeGuessers($container));
    }

    private function processFormTypes(ContainerBuilder $container): Reference
    {
        // Get service locator argument         $servicesMap = [];
        $namespaces = ['Symfony\Component\Form\Extension\Core\Type' => true];

        // Builds an array with fully-qualified type class names as keys and service IDs as values         foreach ($container->findTaggedServiceIds('form.type', true) as $serviceId => $tag) {
            // Add form type service to the service locator