class_docstr: Comment on using `barrier`: If this flag is passed, then all
  the caller processes will wait till all reach the timing routine.
  It is up to the user to make sure all the ranks in `barrier_group`
  call it otherwise, it will result in a hang.
  Comment on `barrier_group`: By default it is set to None which
  in torch distributed land, it will result in the global communicator.
class_docstr_tok: ["Comment","on","using","`","barrier","`",":","If","this","flag","is","passed",",","then","all","the","caller","processes","will","wait","till","all","reach","the","timing","routine",".","It","is","up","to","the","user","to","make","sure","all","the","ranks","in","`","barrier_group","`","call","it","otherwise",",","it","will","result","in","a","hang",".","Comment","on","`","barrier_group","`",":","By","default","it","is","set","to","None","which","in","torch","distributed","land",",","it","will","result","in","the","global","communicator","."]
docstr: Calculate the elapsed time.
docstr_tok: ["Calculate","the","elapsed","time","."]
code: def elapsed(self, reset=True, barrier=False):
      """Calculate the elapsed time."""
      _started = self._started
      # If the timing in progress, end it first.
      if self._started:
          self.stop(barrier=barrier)
      # Get the elapsed time.
      _elapsed = self._elapsed
      # Reset the elapsed time
      if reset:
          self.reset()
      # If timing was in progress, set it back.
      if _started:
          self.start(barrier=barrier)
      return _elapsed
  
imports: from abc import ABC
  from abc import abstractmethod
  import time
  import torch
label_desc: Use image node_id 6 for calling the Timer obj's underlying member method code with example usage: obj.elapsed(reset, barrier) and returns: _elapsed