class_docstr: gowalla dataset
class_docstr_tok: ["gowalla","dataset"]
code: def trainDataSize(self):
      return self.traindataSize
  
imports: import os
  from os.path import join
  import sys
  import paddle
  import numpy
  import pandas
  from paddle.io import Dataset, DataLoader
  from scipy.sparse import csr_matrix
  import scipy.sparse
  from time import time
label_desc: Use image node_id 4 for calling the Loader obj's underlying member method code with example usage: obj.trainDataSize() and returns: self