public function validateFile($fileName, $schemaFile = null, $failOnErrors = false)
    {

        // if we did not get a schema file we have to check if we know which one to use
        if (is_null($schemaFile)) {
            $this->findSchemaFile($fileName);
            $schemaFile = $this->schemaFile;
        }

        // validate the passed configuration file
        ConfigurationUtils::singleton()->validateFile($fileName, $schemaFile, $failOnErrors);
    }