public function loadSchemaFile(): Schema
    {
        if (!file_exists($this->schemaFile)) {
            return new Schema();
        }

        $content = file_get_contents($this->schemaFile);
        $desc = Yaml::parse($content);
        if (empty($desc)) {
            return new Schema();
        }

        $builder = new SchemaBuilder();
        return $builder->build($desc['schema']);
    }