docs: def get_firmware_update_progress(self):
          """Get the progress of the firmware update.
  
          :returns: firmware update state, one of the following values:
                    "Idle","Uploading","Verifying","Writing",
                    "Updating","Complete","Error".
                    If the update resource is not found, then "Unknown".
          :returns: firmware update progress percent
          """
          # perform refresh
          try:
              self.refresh()
          except sushy.exceptions.SushyError as e:
              msg = (('Progress of firmware update not known. '
                      'Error %(error)s') %
                     {'error': str(e)})
              LOG.debug(msg)
              return "Unknown", "Unknown"
  
          # NOTE: Percentage is returned None after firmware flash is completed.
          return (self.firmware_state, self.firmware_percentage)