__rlshift__, __ror__ in Python

I noticed that this recipe seems to use __rlshift__, __ror__ like operators. But, they aren't in the documentation! Can anyone explain these and perhaps po开发者_如何学Pythonint to some docs?

See the documentation for:

• object.__rlshift__()
• object.__ror__()

__rlshift__ is the swapped operands version of __lshift__, used when the right-hand operand supports the operation but the left-hand operand doesn't.