    # File lib/fog/aws/requests/rds/modify_db_instance.rb, line 29
            def modify_db_instance(db_name, apply_immediately, options={})

              if security_groups = options.delete('DBSecurityGroups')
                options.merge!(Fog::AWS.indexed_param('DBSecurityGroups.member.%d', [*security_groups]))
              end

              request({
                'Action'  => 'ModifyDBInstance',
                'DBInstanceIdentifier' => db_name,
                'ApplyImmediately' => apply_immediately,
                :parser   => Fog::Parsers::AWS::RDS::ModifyDBInstance.new,
              }.merge(options))
            end