# File lib/fog/aws/requests/rds/describe_db_reserved_instances.rb, line 15
        def describe_db_reserved_instances(identifier=nil, opts={})
          params = {}
          params['ReservedDBInstanceId'] = identifier if identifier
          if opts[:marker]
            params['Marker'] = opts[:marker]
          end
          if opts[:max_records]
            params['MaxRecords'] = opts[:max_records]
          end
          
          request({
            'Action'  => 'DescribeReservedDBInstances',
            :parser   => Fog::Parsers::AWS::RDS::DescribeDBReservedInstances.new
          }.merge(params))
        end