code: def string_support(py3enc):
      '''Create byte-to-string and string-to-byte conversion functions for
      internal use.
  
      :param py3enc: Encoding used by Python 3 environment.
      :type py3enc: str
      '''
      if sys.version < '3':
          def bytes2str(b):
              '''Identity, returns the argument string (bytes).'''
              return b
          def str2bytes(s):
              '''Identity, returns the argument string (bytes).'''
              return s
      else:
          def bytes2str(b):
              '''Transforms bytes into string (Unicode).'''
              return b.decode(py3enc)
          def str2bytes(u):
              '''Transforms Unicode into string (bytes).'''
              return u.encode(py3enc)
      return (bytes2str, str2bytesf string_support(py3enc):
      '''Create byte-to-string and string-to-byte conversion functions for
      internal use.
  
      :param py3enc: Encoding used by Python 3 environment.
      :type py3enc: str
      '''
      if sys.version < '3':
          def bytes2str(b):
              '''Identity, returns the argument string (bytes).'''
              return b
          def str2bytes(s):
              '''Identity, returns the argument string (bytes).'''
              return s
      else:
          def bytes2str(b):
              '''Transforms bytes into string (Unicode).'''
              return b.decode(py3enc)
          def str2bytes(u):
              '''Transforms Unicode into string (bytes).'''
              return u.encode(py3enc)
      return (bytes2str, str2bytes)
docs: Create byte-to-string and string-to-byte conversion functions for
      internal use.
  
      :param py3enc: Encoding used by Python 3 environment.
      :type py3enc: str