protected function getDefinition(): DefinitionInterface
    {
        if ($this->definition === null) {
            $this->definition = (new Definition())
                ->addOption(new Option('verbose', 'Be more verbose.', 'v', 'verbose', true, true))
                ->addOption(new Option('help', 'Show help about shell or command.', 'h', 'help'));
        }

        return $this->definition;
    }