private function executeComposerInstall($host)
    {
        $ssh = $host->getSshClient();
        $ssh->exec(array(
            sprintf('cd %s;', $host->getWorkingDirectory()),
            'stat composer.phar'
        ));
        if ($ssh->getExitCode()) {
            $this->installComposer($host);
        }
        $ssh = $host->getSshClient();
        $ssh->exec(
            array(
                sprintf('cd %s;', $host->getWorkingDirectory()),
                'php composer.phar install --no-dev'
            ),
            null,
            self::TIMEOUT_MAX_RUNTIME_COMPOSER_INSTALL
        );
        if ($ssh->getExitCode()) {
            throw new SynchronisationException($host->getName(), sprintf(
                'Unable to execute composer install: "%s".',
                $ssh->getErrorOutput()
            ));
        }
    }