Train on my own dataset , got an error: assert batch_size <= ds.size()

[zhaoleo1111]

loading annotations into memory...
Done (t=0.00s)
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index created!
loading annotations into memory...
Done (t=0.00s)
creating index...
index created!
Loading dataset /content/keras_Realtime_Multi-Person_Pose_Estimation/dataset/train ...
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Loading dataset /content/keras_Realtime_Multi-Person_Pose_Estimation/dataset/val ...
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Traceback (most recent call last):
File "train_pose.py", line 208, in
batch_df = batch_dataflow(df, batch_size)
File "/content/keras_Realtime_Multi-Person_Pose_Estimation/training/dataset.py", line 212, in batch_dataflow
df = BatchData(df, batch_size, use_list=True)
File "/usr/local/lib/python3.6/dist-packages/tensorpack/dataflow/common.py", line 95, in init
assert batch