code: def check_file(self, data_files):
      for data_file in data_files:
          if not os.path.exists(data_file):
              return False
      return True
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import os
  import shutil
  import sys
  import tf_euler
  from euler.tools.generate_euler_data import EulerGenerator
label_desc: Use image node_id 4 for calling the DataSet obj's underlying member method code with example usage: obj.check_file(data_files) and returns: True, False