    # File lib/fog/aws/requests/rds/describe_db_parameter_groups.rb, line 38
            def describe_db_parameter_groups(name=nil, opts={})
              response = Excon::Response.new
              parameter_set = []
              if name
                if server = self.data[:parameter_groups][name]
                  parameter_set << server
                else
                  raise Fog::AWS::RDS::NotFound.new("DBInstance #{name} not found")
                end
              else
                parameter_set = self.data[:parameter_groups].values
              end

              response.status = 200
              response.body = {
                "ResponseMetadata"=>{ "RequestId"=> Fog::AWS::Mock.request_id },
                "DescribeDBParameterGroupsResult" => { "DBParameterGroups" => parameter_set }
              }
              response
            end