class_docstr: Hook used to trigger the profiling features of VISSL
code: def on_exception(self, task: "tasks.ClassyTask"):
      if self.profile_by_layer_memory:
          iteration = task.local_iteration_num
          self._dump_memory_stats(iteration)
      if self.profile_runtime:
          self._dump_runtime_profiling_results(stop_profiler=True)
  
imports: import logging
  import os
  import torch
  import torch.nn
  from classy_vision import tasks
  from classy_vision.hooks.classy_hook import ClassyHook
  from fairscale.nn import FullyShardedDataParallel
  from fairscale.nn.misc import FlattenParamsWrapper
  from torch.nn import SyncBatchNorm
  from vissl.config.attr_dict import AttrDict
  from vissl.utils.env import get_machine_local_and_dist_rank
  from vissl.utils.layer_memory_tracking import LayerwiseMemoryTracker
  from vissl.utils.profiler import create_runtime_profiler
label_desc: Use image node_id 4 for calling the ProfilingHook obj's underlying member method code with example usage: obj.on_exception(task) without return types