code: def Start(self):
      
      filename = '{0:s}-{1:s}.csv.gz'.format(
          self._FILENAME_PREFIX, self._identifier)
      if self._path:
        filename = os.path.join(self._path, filename)
  
      self._sample_file = gzip.open(filename, 'wb')
      self._WritesString(self._FILE_HEADER)
  
      self._start_time = time.time()
docs: Starts the profiler.