code: def refresh(self):
          
          key = '%s/refresh' % self.key
          self._server.query(key, method=self._server._session.put)
docs: Refreshing a Library or individual item causes the metadata for the item to be
              refreshed, even if it already has metadata. You can think of refreshing as
              "update metadata for the requested item even if it already has some". You should
              refresh a Library or individual item if:
  
              * You've changed the Library Metadata Agent.
              * You've added "Local Media Assets" (such as artwork, theme music, external
                  subtitle files, etc.)
              * You want to freshen the item posters, summary, etc.
              * There's a problem with the poster image that's been downloaded.
              * Items are missing posters or other downloaded information. This is possible if
                  the refresh process is interrupted (the Server is turned off, internet
                  connection dies, etc).