      Defined in :numref:`sec_object-detection-dataset`"""
      train_iter = paddle.io.DataLoader(BananasDataset(is_train=True),
                                               batch_size=batch_size, shuffle=True)
      val_iter = paddle.io.DataLoader(BananasDataset(is_train=False),
                                             batch_size=batch_size)
      return train_iter, val_iter
  
  d2l.DATA_HUB['voc2012'] = (d2l.DATA_URL + 'VOCtrainval_11-May-2012.tar',
                             '4e443f8a2eca6b1dac8a6c57641b67dd40621a49')
  
 
</s> remove     train_iter = paddle.io.DataLoader(dataset=train_set, batch_size=batch_size,
 </s> add     train_iter = paddle.io.DataLoader(dataset=train_set, batch_size=batch_size, return_list=True, </s> remove         dataset, batch_size=batch_size, shuffle=True,
 </s> add         dataset, batch_size=batch_size, shuffle=True, return_list=True, </s> remove         drop_last=True, num_workers=num_workers)
 </s> add         drop_last=True, return_list=True, num_workers=num_workers) </s> remove         shuffle=True, drop_last=True, num_workers=num_workers)
 </s> add         shuffle=True, return_list=True, drop_last=True, num_workers=num_workers)
                                           batch_size=batch_size, return_list=True)
      Defined in :numref:`sec_object-detection-dataset`"""
      train_iter = paddle.io.DataLoader(BananasDataset(is_train=True),
                                               batch_size=batch_size, shuffle=True)
      val_iter = paddle.io.DataLoader(BananasDataset(is_train=False),
                                           batch_size=batch_size, return_list=True)
      return train_iter, val_iter
  
  d2l.DATA_HUB['voc2012'] = (d2l.DATA_URL + 'VOCtrainval_11-May-2012.tar',
                             '4e443f8a2eca6b1dac8a6c57641b67dd40621a49')
  
keep keep keep keep replace keep keep keep keep keep
 [PaddlePaddle]Remove multi gpu training (#1205)

* Remove multi gpu training

* Try to Add return list for avoiding runtime error

* Set num_workers to 0

* Remove numbers of fcn.md

* Fix natural-language-inference-attention.md&bert-pretraining.md 
d2l/paddle.py