private function getUser(InputInterface $input, OutputInterface $output)
    {
        if ($user = $input->getOption('user')) {
            return $user;
        }
        if ($user = $this->getTransifexConfigValue('/user')) {
            $this->writelnVerbose($output, 'Using transifex user specified in config.');

            return $user;
        }
        if ($user = getenv('transifexuser')) {
            $this->writelnVerbose($output, 'Using transifex user specified in environment.');

            return $user;
        }
        if ($input->isInteractive()) {
            /** @var \Symfony\Component\Console\Helper\QuestionHelper $dialog */
            $dialog = $this->getHelperSet()->get('question');
            if ($user = $dialog->ask($input, $output, new Question('Transifex user:'))) {
                return $user;
            }
        }

        throw new \RuntimeException(
            'Error: you must either specify an username on the commandline or run interactive.'
        );
    }