code: def __die(self, synchronous=False):
          
          already_killed = self.__killed
          self.__killed = True
          if self.__id and not already_killed:
              address = _CursorAddress(
                  self.__address, self.__collection.full_name)
              if synchronous:
                  self.__collection.database.client._close_cursor_now(
                      self.__id, address, session=self.__session)
              else:
                  # The cursor will be closed later in a different session.
                  self.__collection.database.client._close_cursor(
                      self.__id, address)
          self.__end_session(synchronous)
docs: Closes this cursor.