docs: def MI_method_PY3(cls):
      '''class decorator to change MIMapping method names for PY3 compatibility'''
  
      nmspc = cls.__dict__.copy()
      for m in ['__cmp__', 'has_key']:
          nmspc.pop(m)
      methods = ['keys', 'values', 'items']
      for m in methods:
          nmspc[m] = nmspc.pop('view' + m)
      return type(cls)(cls.__name__, cls.__bases__, nmspc)