src/Storage/FileStorage.php
protected function validateConfiguration($userConfig = array())
    {
        if (!$this->configurator) {
            throw new \RuntimeException("Configurator class is not set.");
        }
        
        try {
            return $this->configurator->validate($userConfig);
        } catch (ConfigurationException $e) {
            $e->addBeforeMessage("Configuration error in ".static::CONFIG_FILE.":");
            throw $e;
        }
    }
protected function validateConfiguration($userConfig = array())
    {
        if (!$this->configurator) {
            throw new \RuntimeException("Configurator class is not set.");
        }
        
        try {
            return $this->configurator->validate($userConfig);
        } catch (ConfigurationException $e) {
            $e->addBeforeMessage("Configuration error in ".static::CONFIG_FILE.":");
            throw $e;
        }
    }
Configuration validation

Calls the specific configurator instance, which validates the user
provided configuration and adds default values.

@param mixed $userConfig Anything read from the configuration file
@return array Modified configuration (added defaults)
@throws \RuntimeException Missing configurator
@throws ConfigurationException Validation error