code: def reset_stream(stream):
      
      try:
          position = stream.tell()
      except Exception:
          position = True
      if position != 0:
          try:
              stream.seek(0)
          except Exception:
              message = 'It\'s not possible to reset this stream'
              raise exceptions.TabulatorException(message)
docs: Reset stream pointer to the first element.
  
      If stream is not seekable raise Exception.