new_contents: """Compatibility helpers for Py2 and Py3."""
  from __future__ import division
  from __future__ import absolute_import
  from __future__ import print_function
  from __future__ import unicode_literals
  
  import sys
  
  
  PY2 = sys.version_info.major == 2
  PY3 = not PY2
  
  # Provide a nice range function for py2.
  try:
      range = xrange
  except NameError:
      pass
  
subject: Add py2/py3 compatibility module