code: def test_dataflow_timer_handlers_profiler():
      true_dataflow_time_per_ele = 0.1
      true_max_epochs = 1
      true_num_iters = 2
  
      def dummy_data_loader(data):
          while True:
              for d in data:
                  time.sleep(true_dataflow_time_per_ele)
                  yield d
  
      dummy_data = range(true_num_iters)
  
      profiler = HandlersTimeProfiler()
      dummy_trainer = Engine(_do_nothing_update_fn)
      profiler.attach(dummy_trainer)
      dummy_trainer.run(
          dummy_data_loader(dummy_data),
          max_epochs=true_max_epochs,
          epoch_length=true_num_iters,
      )
      results = profiler.get_results()
      dataflow_results = results[-1]
  
      assert dataflow_results[0] == "Dataflow"
      # event name
      assert dataflow_results[1] == "None"
      # total
      assert dataflow_results[2] == approx(
          true_num_iters * true_dataflow_time_per_ele, abs=1e-1
      )
      # min
      assert dataflow_results[3][0] == approx(
          true_dataflow_time_per_ele, abs=1e-1
      )
      # max
      assert dataflow_results[4][0] == approx(
          true_dataflow_time_per_ele, abs=1e-1
      )
      # mean
      assert dataflow_results[5] == approx(
          true_dataflow_time_per_ele, abs=1e-1
      )
      # stddev
      assert dataflow_results[6] == approx(0.0, abs=1e-1)
  
imports: import sys
  import time
  from unittest.mock import patch
  import pytest
  from pytest import approx
  from ignite.engine import Engine, EventEnum, Events
  from ignite.handlers.time_profilers import BasicTimeProfiler, HandlersTimeProfiler
label_desc: Use image node_id 6 for calling a global function with example usage: test_dataflow_timer_handlers_profiler() without return types