code: def rewind_body(body, body_pos):
      
      body_seek = getattr(body, 'seek', None)
      if body_seek is not None and isinstance(body_pos, integer_types):
          try:
              body_seek(body_pos)
          except (IOError, OSError):
              raise UnrewindableBodyError("An error occurred when rewinding request "
                                          "body for redirect/retry.")
      elif body_pos is _FAILEDTELL:
          raise UnrewindableBodyError("Unable to record file position for rewinding "
                                      "request body during a redirect/retry.")
      else:
          raise ValueError("body_pos must be of type integer, "
                           "instead it was %s." % type(body_pos))
docs: Attempt to rewind body to a certain position.
      Primarily used for request redirects and retries.
  
      :param body:
          File-like object that supports seek.
  
      :param int pos:
          Position to seek to in file.