code: def run(self):
          
          self._running.set()
          self._status = TransferState.RUNNING
          self._time_started = time.time()
  
          # Initializes the upload
          self._initialize_upload()
  
          # Opens the file for reading in binary mode.
          try:
              with io.open(self._file_path, mode='rb') as fp:
                  # Creates a partitioned file
                  parted_file = UPartedFile(
                      fp, self._file_size, self._part_size, self._upload_id,
                      self._retry, self._timeout, self.session, self._api
                  )
  
                  # Iterates over parts and submits them for upload.
                  for _ in parted_file:
                      if self._stop_signal:
                          return
                      self._running.wait()
                      self._bytes_done += self._part_size
                      # If the progress callback is set we need to provide a
                      # progress object for it.
                      if self._progress_callback:
                          progress = Progress(
                              parted_file.total, parted_file.total_submitted,
                              self._bytes_done, self._file_size, self.duration
                          )
                          self._progress_callback(progress)
          except IOError:
              raise SbgError('Unable to open file {}'.format(self._file_path))
          except Exception as e:
              # If the errorback callback is set call it with status
              self._status = TransferState.FAILED
              if self._errorback:
                  self._errorback(self._status)
              else:
                  raise SbgError(six.text_type(e))
  
          # Finalizes the upload.
          self._finalize_upload()
          self._status = TransferState.COMPLETED
          # If the callback is set call it.
          if self._callback:
              self._callback(self._status)
docs: Runs the thread! Should not be used use start() method instead.