On Thu, Aug 24, 2017, at 02:21 PM, xoviat wrote:
I mean is this golang or Python? In Python, you raise notimplementederror.

But there's a NotImplemented singleton in Python as well. The argument for using a return value is that the hook code has to deliberately return that, whereas a NotImplementedError could bubble up from some internal call, in which case it should really be registered as an error.