docs: def barrier():
      """
      Works as a temporary distributed barrier, currently pytorch
      doesn't implement barrier for NCCL backend.
      Calls all_reduce on dummy tensor and synchronizes with GPU.
      """
      if torch.distributed.is_available() and torch.distributed.is_initialized():
          torch.distributed.all_reduce(torch.cuda.FloatTensor(1))
          torch.cuda.synchronize()