# File lib/fog/aws/requests/rds/describe_orderable_db_instance_options.rb, line 21
        def describe_orderable_db_instance_options(engine=nil, opts={})
          params = {}
          params['Engine'] = engine if engine
          params['DBInstanceClass'] = opts[:db_instance_class] if opts[:db_instance_class]
          params['EngineVersion'] = opts[:engine_version] if opts[:engine_version]
          params['LicenseModel'] = opts[:license_model] if opts[:license_model]
          params['Marker'] = opts[:marker] if opts[:marker]
          params['MaxRecords'] = opts[:max_records] if opts[:max_records]
          params['Vpc'] = opts[:vpc] if opts[:vpc]

          request({
            'Action'  => 'DescribeOrderableDBInstanceOptions',
            :parser   => Fog::Parsers::AWS::RDS::DescribeOrderableDBInstanceOptions.new
          }.merge(params))
        end