xDeepfm can't save model

[RisanLi]

If I code 'model.save_weights(...)' after model.fit in xDeepfm, then i get the traceback:

Traceback (most recent call last):
File "train_xdeepfm.py", line 74, in
model.save_weights('weights/test.h5')
File "/home/lixiang/anaconda3/envs/env_tf2/lib/python3.6/site-packages/tensorflow_core/python/keras/engine/network.py", line 1074, in save_weights
saving.save_weights_to_hdf5_group(f, self.layers)
File "/home/lixiang/anaconda3/envs/env_tf2/lib/python3.6/site-packages/tensorflow_core/python/keras/saving/hdf5_format.py", line 631, in save_weights_to_hdf5_group
param_dset = g.create_dataset(name, val.shape, dtype=val.dtype)
File "/home/lixiang/anaconda3/envs/env_tf2/lib/python3.6/site-packages/h5py/_hl/group.py", line 139, in create_dataset
self[name] = dset
File "/home/lixiang/anaconda3/envs/env_tf2/lib/python3.6/site-packages/h5py/_hl/group.py", line 373, in setitem
h5o.link(obj.id, self.id, name, lcpl=lcpl, lapl=self._lapl)
File "h5py/_objects.pyx", line 54, in h5py._objects.with_phil.wrapper
File "h5py/_objects.pyx", line 55, in h5py._objects.with_phil.wrapper
File "h5py/h5o.pyx", line 202, in h5py.h5o.link
RuntimeError: Unable to create link (name already exists)

However i changed model from xdeepfm to deepfm, model.save_weights() ran successfully.
Whats wrong with the xdeepfm ?

thanks.