new_contents: # Copyright Least Authority Enterprises.
  # See LICENSE for details.
  
  """
  Helpers for Python 2/3 compatibility.
  """
  
  from twisted.python.compat import _PY3
  
  def encode_environ(env):
      """
      Convert a ``dict`` of ``unicode`` keys and values to ``bytes`` on Python 2,
      but return the ``dict`` unmodified on Python 3.
      """
      if _PY3:
          return env
      else:
          bytes_env = {}
          for key in env:
              bytes_env[key.encode("ascii")] = env[key].encode("ascii")
          return bytes_env
  
subject: Add helper for Python 2/3 compatibility.