# File lib/new_relic/agent/payload_metric_mapping.rb, line 16
        def append_mapped_metrics(txn_metrics, sample)
          if txn_metrics
            SPEC_MAPPINGS.each do |(name, extracted_values)|
              if txn_metrics.has_key?(name)
                stat = txn_metrics[name]
                extracted_values.each do |value_name, key_name|
                  sample[key_name] = stat.send(value_name)
                end
              end
            end
          end
        end