# File lib/new_relic/agent/samplers/vm_sampler.rb, line 71
        def record_delta(snapshot, key, metric, txn_count) #THREAD_LOCAL_ACCESS
          value = snapshot.send(key)
          if value
            delta = value - @last_snapshot.send(key)
            NewRelic::Agent.agent.stats_engine.tl_record_unscoped_metrics(metric) do |stats|
              stats.call_count      += txn_count
              stats.total_call_time += delta
            end
          end
        end