centerpoint模型说明

1、调试时，执行到 for i, data_batch in enumerate(data_loader):时，第一次ok，第二次卡主了。网上给出的解决方法是将加载器DataLoader参数num_workers设为1

        batch_size = num_gpus * batch_size
        num_workers = num_gpus * workers_per_gpu

    # TODO change pin_memory
    data_loader = DataLoader(
        dataset,
        batch_size=batch_size,
        sampler=sampler,
        shuffle=(sampler is None),
        num_workers=num_workers,
        collate_fn=collate_kitti,
        # pin_memory=True,
        pin_memory=False,
    )