code: def split_dataset(df):
      train_data, test_data = train_test_split(
          df, test_size=0.2, random_state=100
      )
      return train_data, test_data
  
file_path: BigDL/python/orca/tutorial/NCF/process_xshards.py
imports: import os
  import numpy
  import pandas
  import scipy.sparse
  from sklearn.model_selection import train_test_split
  from bigdl.orca.data.pandas import read_csv
  from bigdl.orca.data.transformer import StringIndexer, MinMaxScaler
label_desc: Use image node_id 2 for calling a global function with example usage: split_dataset(df) and returns: train_data,  test_data