code: def async_saves(cls):
          
          cls._local.save_exec = ThreadPoolExecutor(
              max_workers=ASYNC_SAVE_THREADS
          )
          return cls._local.save_exec
docs: Returns a context manager to allow asynchronously creating subjects.
          Using this context manager will create a pool of threads which will
          create multiple subjects at once and upload any local files
          simultaneously.
  
          The recommended way to use this is with the `with` statement::
  
              with Subject.async_saves():
                  local_files = [...]
                  for filename in local_files:
                      s = Subject()
                      s.links.project = 1234
                      s.add_location(filename)
                      s.save()
  
          Alternatively, you can manually shut down the thread pool::
  
              pool = Subject.async_saves()
              local_files = [...]
              try:
                  for filename in local_files:
                      s = Subject()
                      s.links.project = 1234
                      s.add_location(filename)
                      s.save()
              finally:
                  pool.shutdown()