public function isConfigValid(array $config)
    {
        $isValid = true;

        foreach ($this->configValidators as $configValidator) {
            $configName = $configValidator->getConfigName();

            if (!isset($config[$configName])) {
                throw new InvalidImageConfigException(sprintf('Invalid image config: %s', $configName));
            }

            $isValid = $isValid && $configValidator->validate($config[$configName], $this->defaultConfig);
        }

        return $isValid;
    }