getFqcnTypeClass example

if ($input->getOption('show-deprecated')) {
                $options['core_types'] = $this->filterTypesByDeprecated($options['core_types']);
                $options['service_types'] = $this->filterTypesByDeprecated($options['service_types']);
            }
            $options['extensions'] = $this->extensions;
            $options['guessers'] = $this->guessers;
            foreach ($options as $k => $list) {
                sort($options[$k]);
            }
        } else {
            if (!class_exists($class) || !is_subclass_of($class, FormTypeInterface::class)) {
                $class = $this->getFqcnTypeClass($input, $io, $class);
            }
            $resolvedType = $this->formRegistry->getType($class);

            if ($option = $input->getArgument('option')) {
                $object = $resolvedType->getOptionsResolver();

                if (!$object->isDefined($option)) {
                    $message = sprintf('Option "%s" is not defined in "%s".', $option, $resolvedType->getInnerType()::class);

                    if ($alternatives = $this->findAlternatives($option, $object->getDefinedOptions())) {
                        if (1 === \count($alternatives)) {