code: def _get_analysis(self, comm):
      def _analyse_gpu_cost_time(result, threshold):
          aver = np.mean(result, axis=0)[1]
          _node_l = [*filter(lambda n: n[1] > aver * threshold, result)]
          if len(_node_l):
              ranks = ", ".join([str(int(n[0])) for n in _node_l])
              _str = (
                  "Gpu of Rank {} ran slower than average "
                  "by a factor of {} or more".format(ranks, threshold)
              )
              return _str
          return ""
  
      result = self._reap_multinode_data(comm)
      if comm.rank == 0:
          error_str = _analyse_gpu_cost_time(
              result, self._error_threshold
          )
          if error_str:
              logger.error(error_str)
              raise Exception(error_str)
          else:
              warning_str = _analyse_gpu_cost_time(
                  result, self._warning_threshold
              )
              if warning_str:
                  logger.warning(warning_str)
  
imports: import os
  import re
  import timeit
  from contextlib import contextmanager
  import nnabla
  import nnabla.utils.callback
  import numpy
  from nnabla.config import nnabla_config
  from nnabla.logger import logger
  from nnabla.utils import nnabla_pb2
  from nnabla.utils.communicator_util import current_communicator
  from nnabla.utils.get_file_handle import get_file_handle_save, get_decorated_file_loader, load_files
  from contextlib import contextmanager
  import nnabla.logger
  from nnabla.lms import SwapInOutScheduler
label_desc: Use image node_id 6 for calling the NodeTimeInfoCollector obj's underlying member method code with example usage: obj._get_analysis(comm) and returns: str, _str