code: def unable_thread_pool(self, only_read=False):
          
          if self.enable_thread_pool and hasattr(self, 'thread_pool') and self.thread_pool is not None:
              self.thread_pool.shutdown()
              self.thread_pool = None
              self.enable_thread_pool = False
              self.logger.debug('Remove thread pool completed')
              return True
          else:
              self.logger.warning('Current not have a thread pool is existent')
              return False
docs: >>> cache = Cache(log_level=logging.WARNING)
          >>> cache.unable_thread_pool()
          True
          >>> cache.unable_thread_pool()
          False