code: def test_aggregated_traces(device):
      import torch
      from torch.optim import SGD
      from speechbrain.core import Brain
      from speechbrain.utils.profiling import profile
  
      @profile
      class SimpleBrain(Brain):
          def compute_forward(self, batch, stage):
              return self.modules.model(batch[0])
  
          def compute_objectives(self, predictions, batch, stage):
              return torch.nn.functional.l1_loss(predictions, batch[1])
  
      model = torch.nn.Linear(
          in_features=10, out_features=10, device=device
      )
      inputs = torch.rand(10, 10, device=device)
      targets = torch.rand(10, 10, device=device)
      train_set = ([inputs, targets],)
      valid_set = ([inputs, targets],)
      test_set = (
          [inputs, targets],
          [inputs, targets],
      )
  
      # Profiling: __init__ constructor -- while scheduler: waiting --> nothing to report
      brain = SimpleBrain(
          {"model": model},
          lambda x: SGD(x, 0.1),
          run_opts={"device": device},
      )
  
      # Profiling: empty traces
      assert len(brain.profiler.speechbrain_event_traces) == 1
      """
      init_report = brain.profiler.merge_traces()
      assert len(init_report) >= 1
      # assert len(init_report) >= 4  # == 6  # before; config dependent: 7
      assert len(brain.profiler.speechbrain_event_traces) == 1
      " ""print(brain.profiler.key_averages().table(sort_by="cpu_time_total", row_limit=10))
      -------------------------------------------  ------------  ------------  ------------  ------------  ------------  ------------
                                             Name    Self CPU %      Self CPU   CPU total %     CPU total  CPU time avg    # of Calls
      -------------------------------------------  ------------  ------------  ------------  ------------  ------------  ------------
          aten::_has_compatible_shallow_copy_type        80.00%      12.000us        80.00%      12.000us       3.000us             4
                                         aten::to        20.00%       3.000us        20.00%       3.000us       1.500us             2
      -------------------------------------------  ------------  ------------  ------------  ------------  ------------  ------------
      Self CPU time total: 15.000us
  
      print(init_report.key_averages().table(sort_by="cpu_time_total", row_limit=10))
      -------------------------------------------  ------------  ------------  ------------  ------------  ------------  ------------
                                             Name    Self CPU %      Self CPU   CPU total %     CPU total  CPU time avg    # of Calls
      -------------------------------------------  ------------  ------------  ------------  ------------  ------------  ------------
          aten::_has_compatible_shallow_copy_type        80.00%      12.000us        80.00%      12.000us       3.000us             4
                                         aten::to        20.00%       3.000us        20.00%       3.000us       1.500us             2
      -------------------------------------------  ------------  ------------  ------------  ------------  ------------  ------------
      Self CPU time total: 15.000us
      """
  
      brain.fit(
          epoch_counter=range(10),
          train_set=train_set,
          valid_set=valid_set,
      )
      assert len(brain.profiler.speechbrain_event_traces) == 2
      # assert len(brain.profiler.speechbrain_event_traces[0]) >= 4  # == 6  # before; config dependent: 7
      # assert len(brain.profiler.speechbrain_event_traces[1]) >= 2500  # 2862 with torch==1.10.1
      # assert len(brain.profiler.events()) >= 2500  # 2832 with torch==1.10.1
      # assert len(brain.profiler.events().key_averages()) >= 60  # 72 with torch==1.10.1
      """print(brain.profiler.events().key_averages().table(sort_by="cpu_time_total", row_limit=10))
      -------------------------------------------------------  ------------  ------------  ------------  ------------  ------------  ------------
                                                         Name    Self CPU %      Self CPU   CPU total %     CPU total  CPU time avg    # of Calls
      -------------------------------------------------------  ------------  ------------  ------------  ------------  ------------  ------------
                                                aten::l1_loss         2.39%     415.000us        25.28%       4.392ms     109.800us            40
      enumerate(DataLoader)#_SingleProcessDataLoaderIter._...        12.65%       2.198ms        20.06%       3.485ms      87.125us            40
                                                 aten::linear         1.41%     245.000us        13.24%       2.299ms     114.950us            20
                                                     aten::to         2.04%     354.000us        10.59%       1.839ms      11.494us           160
                                               aten::isfinite         2.12%     369.000us         9.87%       1.714ms      57.133us            30
                                                   aten::mean         1.13%     196.000us         9.15%       1.589ms      79.450us            20
                                                  aten::stack         2.33%     404.000us         8.94%       1.553ms      31.060us            50
                                               aten::_to_copy         5.67%     985.000us         8.67%       1.506ms      15.060us           100
                                                 aten::matmul         1.57%     273.000us         7.83%       1.360ms      68.000us            20
                                       aten::l1_loss_backward         1.22%     212.000us         6.67%       1.158ms      57.900us            20
      -------------------------------------------------------  ------------  ------------  ------------  ------------  ------------  ------------
      Self CPU time total: 17.370ms
      """
  
      # Profiling: aggregate traces
      """
      short_report = brain.profiler.merge_traces()
      assert len(short_report) >= 1
      # assert len(short_report) >= 2500  # 2838 with torch==1.10.1
      # assert len(short_report.key_averages()) >= 60  # 73 with torch==1.10.1
      " ""print(short_report.key_averages().table(sort_by="cpu_time_total", row_limit=10))
      -------------------------------------------------------  ------------  ------------  ------------  ------------  ------------  ------------
                                                         Name    Self CPU %      Self CPU   CPU total %     CPU total  CPU time avg    # of Calls
      -------------------------------------------------------  ------------  ------------  ------------  ------------  ------------  ------------
                                                aten::l1_loss         2.39%     415.000us        25.26%       4.392ms     109.800us            40
      enumerate(DataLoader)#_SingleProcessDataLoaderIter._...        12.64%       2.198ms        20.05%       3.485ms      87.125us            40
                                                 aten::linear         1.41%     245.000us        13.22%       2.299ms     114.950us            20
                                                     aten::to         2.05%     357.000us        10.60%       1.842ms      11.370us           162
                                               aten::isfinite         2.12%     369.000us         9.86%       1.714ms      57.133us            30
                                                   aten::mean         1.13%     196.000us         9.14%       1.589ms      79.450us            20
                                                  aten::stack         2.32%     404.000us         8.93%       1.553ms      31.060us            50
                                               aten::_to_copy         5.67%     985.000us         8.66%       1.506ms      15.060us           100
                                                 aten::matmul         1.57%     273.000us         7.82%       1.360ms      68.000us            20
                                       aten::l1_loss_backward         1.22%     212.000us         6.66%       1.158ms      57.900us            20
      -------------------------------------------------------  ------------  ------------  ------------  ------------  ------------  ------------
      Self CPU time total: 17.385ms
      """
  
      brain.evaluate(test_set=test_set)
      brain.evaluate(test_set=test_set)
      brain.evaluate(test_set=test_set)
      assert len(brain.profiler.speechbrain_event_traces) == 5
      # assert len(brain.profiler.speechbrain_event_traces[0]) >= 4  # == 6  # before; config dependent: 7
      # assert len(brain.profiler.speechbrain_event_traces[1]) >= 2500  # 2862 with torch==1.10.1
      # assert len(brain.profiler.speechbrain_event_traces[2]) >= 125  # 143 with torch==1.10.1
      # assert len(brain.profiler.speechbrain_event_traces[3]) >= 125  # 143 with torch==1.10.1
      # assert len(brain.profiler.speechbrain_event_traces[4]) >= 125  # 143 with torch==1.10.1
      # assert len(brain.profiler.events()) >= 125  # 141 with torch==1.10.1
      # assert len(brain.profiler.events().key_averages()) >= 25  # 42 with torch==1.10.1
      # the following is only for the last call of the 3x brain.evaluate()
      """print(brain.profiler.events().key_averages().table(sort_by="cpu_time_total", row_limit=10))
      -------------------------------------------------------  ------------  ------------  ------------  ------------  ------------  ------------
                                                         Name    Self CPU %      Self CPU   CPU total %     CPU total  CPU time avg    # of Calls
      -------------------------------------------------------  ------------  ------------  ------------  ------------  ------------  ------------
                                                aten::l1_loss         3.54%      23.000us        37.38%     243.000us      60.750us             4
      enumerate(DataLoader)#_SingleProcessDataLoaderIter._...        16.62%     108.000us        29.38%     191.000us      63.667us             3
                                                 aten::linear         2.77%      18.000us        20.46%     133.000us      66.500us             2
                                               aten::isfinite         3.54%      23.000us        14.31%      93.000us      46.500us             2
                                                   aten::mean         1.85%      12.000us        12.62%      82.000us      41.000us             2
                                                  aten::stack         3.23%      21.000us        12.15%      79.000us      19.750us             4
                                                 aten::matmul         2.62%      17.000us        11.69%      76.000us      38.000us             2
                                                   aten::div_         2.92%      19.000us         7.54%      49.000us      24.500us             2
                                                     aten::to         1.85%      12.000us         7.08%      46.000us       7.667us             6
                                                     aten::mm         6.31%      41.000us         6.77%      44.000us      22.000us             2
      -------------------------------------------------------  ------------  ------------  ------------  ------------  ------------  ------------
      Self CPU time total: 650.000us
      """
  
      # Profiling: putting previous benchmark reporting together.
      """
      full_report = brain.profiler.merge_traces()
      assert len(full_report) >= 1
      # assert len(full_report.key_averages()) >= 60  # 73 with torch==1.10.1
      # In this minimal example, only 73 functions matter.
      # Some events are duplicated (perhaps from wrapping functions):
      # => they appear stacked & EventList._remove_dup_nodes drops direct child events of same name as their parent.
      num_events = sum([len(x) for x in brain.profiler.speechbrain_event_traces])
      assert num_events >= 1
      # assert num_events >= 3000  # 3297 with torch==1.10.1  # expected: 6 + 2862 + 3x143 = 3297
      # Apparently, this depends on how this test is run (by its own or as part of the entire file's test suite).
      # assert (num_events == len(full_report)) or (len(full_report) == len(set([x.id for x in full_report])))
      # ... not tested, why
      " ""print(full_report.key_averages().table(sort_by="cpu_time_total", row_limit=10))
      -------------------------------------------------------  ------------  ------------  ------------  ------------  ------------  ------------
                                                         Name    Self CPU %      Self CPU   CPU total %     CPU total  CPU time avg    # of Calls
      -------------------------------------------------------  ------------  ------------  ------------  ------------  ------------  ------------
                                                aten::l1_loss         2.21%     427.000us        27.58%       5.326ms     102.423us            52
      enumerate(DataLoader)#_SingleProcessDataLoaderIter._...        11.89%       2.297ms        21.80%       4.210ms      85.918us            49
                                                 aten::linear         1.57%     304.000us        14.61%       2.821ms     108.500us            26
                                               aten::isfinite         2.53%     488.000us        10.72%       2.071ms      57.528us            36
                                                     aten::to         2.03%     392.000us        10.42%       2.013ms      11.183us           180
                                                   aten::mean         1.15%     223.000us         9.81%       1.894ms      72.846us            26
                                                  aten::stack         2.34%     452.000us         9.54%       1.842ms      29.710us            62
                                               aten::_to_copy         5.49%       1.061ms         8.51%       1.643ms      14.670us           112
                                                 aten::matmul         1.65%     318.000us         8.48%       1.638ms      63.000us            26
                                                   aten::div_         1.50%     290.000us         6.95%       1.343ms      47.964us            28
      -------------------------------------------------------  ------------  ------------  ------------  ------------  ------------  ------------
      Self CPU time total: 19.311ms
      """
  
label_desc: Use image node_id 5 for calling a global function with example usage: test_aggregated_traces(device) and returns: self, torch