code: def get_label_cols():
      return ["label"]
  
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 5 for calling a global function with example usage: get_label_cols() and returns: list