I think it's fine the way it is (but I'd also be fine with changing it to `num` or commenting if you/someone wants to do that).

One other thing: these params should be optional and just fail at runtime if unspecified -- required params can never be changed so imo we should just never use them (this is how Google uses protobufs).  (See scary yellow box starting with "Required Is Forever" at https://developers.google.com/protocol-buffers/docs/proto)