code: def uninstall_all_visa_handlers(self, session):
          
  
          if session is not None:
              self.__uninstall_all_handlers_helper(session)
          else:
              for session in list(self.handlers):
                  self.__uninstall_all_handlers_helper(session)
docs: Uninstalls all previously installed handlers for a particular session.
  
          :param session: Unique logical identifier to a session. If None, operates on all sessions.