How to change protocol version when sending ServerHello

[Jay]

This is somewhat related to droptls which just drops the connection upon seeing a client sending versions > 3.0. 

We would like to see if the client falls for or fails to check the server is sending backing a version of 3.0 in its Server Hello (instead of the server just dropping connection). 

I tried looking thru the code but was not clear which method would be the right place to attempt doing this. There are on_ssl, on_request, on_response methods. And am assuming this would need to happen in a connection handler - data handler might be too late. I dont want to change anything else other than the version. Am thinking I would need to write a minimal connection handler with one of its methods (on_ssl, on_request, on_response, what else?) doing the version change. 

Or perhaps if there are any protocol version constants maintained someplace that nogotofail uses when responding that I could change in which case I may not need to do anything special in any of the connections handler methods. Sorry if I overlooked but I will try to search for them again. 

I could not find any documentation on what each of these methods are supposed to do like their semantics. 

thanks

Jay