在使用paddledetection时，无法从 paddle.utils.download 引入 _get_unique_endpoints，paddle版本为2.0.0rc0

W0209 16:29:58.133456 5626 init.cc:157] Compiled with WITH_GPU, but no GPU found in runtime.
Traceback (most recent call last):
File "tools/train.py", line 32, in
from ppdet.core.workspace import load_config, merge_config
File "/home/aistudio/PaddleDetection/ppdet/__init__.py", line 15, in
from . import (core, data, engine, modeling, model_zoo, optimizer, metrics,
File "/home/aistudio/PaddleDetection/ppdet/data/__init__.py", line 15, in
from . import source
File "/home/aistudio/PaddleDetection/ppdet/data/source/__init__.py", line 15, in
from . import coco
File "/home/aistudio/PaddleDetection/ppdet/data/source/coco.py", line 18, in
from .dataset import DetDataset
File "/home/aistudio/PaddleDetection/ppdet/data/source/dataset.py", line 24, in
from ppdet.utils.download import get_dataset_path
File "/home/aistudio/PaddleDetection/ppdet/utils/download.py", line 33, in
from paddle.utils.download import _get_unique_endpoints
ImportError: cannot import name '_get_unique_endpoints' from 'paddle.utils.download' (/opt/conda/envs/python35-paddle120-env/lib/python3.7/site-packages/paddle/utils/download.py)