code: def get(self, id_or_url, default=None):
          
          if '/' in id_or_url:
              id = urls.SheetUrl.from_string(id_or_url).id
          else:
              id = id_or_url
          try:
              return self[id]
          except KeyError:
              return default
docs: Fetch and return the spreadsheet with the given id or url.
  
          Args:
              id_or_url (str): unique alphanumeric id or URL of the spreadsheet
          Returns:
              New SpreadSheet instance or given default if none is found
          Raises:
              ValueError: if an URL is given from which no id could be extracted